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Microbiological & Chemical Exposure Assessment Research Division Publications: 2006

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This page lists publication titles, citations and abstracts produced by NERL's Microbiological & Chemical Exposure Assessment Research Division for the year 2006, organized by Publication Type. Your search has returned 78 Matching Entries.

See also Microbiological & Chemical Exposure Assessment Research Division citations with abstracts: 1999,  2000,  2001,  2002,  2003,  2004,  2005,  2006,  2007,  2008,  2009

Technical Information Manager: Angela Moore - (513) 569-7341 or moore.angela@epa.gov

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Presented/Published
BOOK CHAPTER Giardia Lamblia 01/01/2006
SCHAEFER, F. W. Giardia Lamblia. 2nd.Chapter 31, Waterborne Pathogens AWWA Manual M48. American Water Works Association, Denver, CO, 209-216, (2006).
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

EPA PUBLISHED PROCEEDINGS Colloquium on Water Quality Monitoring and Testing in Latin America and the Carribean 12/29/2006
BISSONETTE, E., G. CARROLL, A. P. DUFOUR, J. A. GOODRICH, B. HENDERSON, L. NEWLAND, C. SODERBERG, F. GILBES, F. ROMAN, I. SANTIAGO, J. R. SANTOS, G. TORANZOS, AND H. SALAS. Colloquium on Water Quality Monitoring and Testing in Latin America and the Carribean. Colloquium on Water Quality Monitoring and Testing in Latin American and the Caribbean, San Juan, PR, October 25 - 27, 2005. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-07/030.
Abstract: Summary Report for presentations given in San Juan, PR, October 25-27, 2005

JOURNAL Detection and Quantification of Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interaction of Arsenosugars With Sulfide as a Function of Ph 12/31/2006
CONKLIN, S., P. A. CREED, AND JOHN T. CREED. Detection and Quantification of Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interaction of Arsenosugars With Sulfide as a Function of Ph. JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. Royal Society of Chemistry, Cambridge, Uk, 21(9):869-875, (2006).
Abstract: The sulfar analog of As(328)(2,3-dihydroxypropyl-5-deoxy-5-dimethylarsinoyl-ß-D-riboside), abbreviated (As(328-S), was detected and quantified in five species of marine shellfish using IC-ICP-MS with structural verification via IC-ESI-MS/MS. The CAD spectra produced from the parent ion m/z 345 in the extract contained two major daughter ions, m/z 253 and 235, closely matching the CAD spectrum of synthetic As(328-S). The ability of the oxide and sulfide forms of the arsenosugar to interconvert led to a series of fundamental studies in ideal solutions containing both the arsenosugar and sulfide. The conversion of As(328) to As(328-S) was found to be pH sensitive, and promoted in the pH range where HS- is converted to H2 (pK1 = 7). The conversion was observed in both shellfish extracts and ideal solutions with comparable sulfide and arsenosugar concentrations. The conversion was further studied over a range of sulfur/arsenic molar ratios. At a 15-fold molar excess of sulfide at pH 4.8, the lowest pH experienced by an extract, > 90% conversion to the sulfide was observed. In the context of shellfish, a molar ratio greater than 200:1 sulfide to arsenic was detected in all five extracts. These trends should prove useful in improving confidence in thio-arsenosugar speciation, and predicting the extent of conversion under a given set of conditions.

JOURNAL Investigation of Sequential and Enzymatic Extraction of Arsenic from Drinking Water Distribution Solids With ICP-MS 12/30/2006
CREED, P. A., C. GALLAWA, A. YOUNG, C. A. SCHWEGEL, D. A. LYTLE, T. J. SORG, AND JOHN T. CREED. Investigation of Sequential and Enzymatic Extraction of Arsenic from Drinking Water Distribution Solids With ICP-MS. JOURNAL OF ENVIRONMENTAL MONITORING. Royal Society of Chemistry, Cambridge, Uk, 8(9):968-972, (2006).
Abstract: A sequential extraction approach was utilized to estimate the distribution of arsenite [As(III)] and arsenate [As(V)] on iron oxide/hydroxide solids obtained from drinking water distribution systems. The arsenic (As) associated with these solids can be segregated into three operational defined categories (exchangeable, amorphous and crystalline) according to the sequential extraction literature. The exchangeable As, for the six drinking water solids evaluated, was estimated using 10mM MgCl2 and 10mM NaH2PO4 and represented between 5-34% of the total As available from the solid. The amorphously bound As was estimated using 10mM (NH4)2C2O4 and represented between 57-124% of the As available from the respective solid. Finally, the crystalline bound As was estimated using titanium citrate and this represented less than 1.5% of the As associated with the solids.
A synthetic stomach / intestine extraction approach was also applied to the distribution solids. The stomach fluid was found to extract between 0.5-33.3µg/g As and 120-2360µg/g iron (Fe). The As concentrations in the intestine fluid were between 0.02-0.04µg/g while the Fe concentration ranged from 0.06-0.7µg/g for the first six drinking water distribution solids. The elevated Fe levels associated with the stomach fluid were found to produce Fe based precipitates when the intestinal treatment was applied. Preliminary observations indicate that most of the aqueous Fe in the stomach fluid is ferric ion and the observed precipitate produced in the intestine fluid is consistent with the decreased solubility of ferric ion at the pH associated with the intestine.


JOURNAL Roles for Cell Wall Glycopeptidolipid in Surface Adherence and Planktonic Dispersal of Mycobacterium Avium 12/01/2006
Freeman, R., H. Geier, K. M. Weigel, J. Do, T. E. Ford, AND G. A. Cangelosi. Roles for Cell Wall Glycopeptidolipid in Surface Adherence and Planktonic Dispersal of Mycobacterium Avium. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. American Society for Microbiology, Washington, DC, 72(12):7554-7558, (2006).
Abstract: The opportunistic pathogen Mycobacterium avium is a significant inhabitant of biofilms in drinking water distribution systems. M. avium expresses on its cell surface serovar-specific glycopeptidolipids (ssGPLs). Studies have implicated the core GPL in biofilm formation by M. avium and by other Mycobacterium species. In order to test this hypothesis in a directed fashion, three model systems were used to examine biofilm formation by mutants of M. avium with transposon insertions into pstAB (also known as nrp and mps). pstAB encodes the nonribosomal peptide synthetase that catalyzes the synthesis of the core GPL. The mutants did not adhere to polyvinyl chloride plates; however, they adhered well to plastic and glass chamber slide surfaces, albeit with different morphologies from the parent strain. In a model that quantified surface adherence under recirculating water, wild-type and pstAB mutant cells accumulated on stainless steel surfaces in equal numbers. Unexpectedly, pstAB mutant cells were >10-fold less abundant in the recirculating-water phase than parent strain cells. These observations show that GPLs are directly or indirectly required for colonization of some, but by no means all, surfaces. Under some conditions, GPLs may play an entirely different role by facilitating the survival or dispersal of nonadherent M. avium cells in circulating water. Such a function could contribute to waterborne M. avium infection.

JOURNAL Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Based Analysis of Giardia Lamblia 11/01/2006
VILLEGAS, E., S. GLASSMEYER, M. W. WARE, S. L. HAYES, AND F. W. SCHAEFER. Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Based Analysis of Giardia Lamblia. JOURNAL OF EUKARYOTIC MICROBIOLOGY. Allen Press, Inc., Lawrence, KS, 53(S1):S179-S-181, (2007).
Abstract: Giardia is the protozoan parasite that is the etiologic agent of giardiasis. This illness is the most common parasitic disease, estimated to infect 2.5 million people in the United States and up to 280 million people worldwide each year [8,19]. Symptoms of giardiasis range from asymptomatic to severe abdominal pain, chronic diarrhea, and in rare cases, death, with young children and immunocompromised individuals being at the greatest risk of serious illness [1,19]. Infection typically occurs through the fecal-oral route and has been documented to be associated with many waterborne disease outbreaks worldwide. A majority of these outbreaks occurred due to contamination of the drinking water supplies with untreated sewage.
There are at least six species of Giardia including Giardia lamblia (also known as Giardia duodenalis or Giardia intestinalis), which can infect a wide range of hosts including humans [4]. The current detection method employed to monitor the presence of Giardia cysts in surface and drinking water relies primarily on microscopic techniques that detect the presence of Giardia cysts in the sample, but the method is not species-specific nor does it determine cyst viability [18]. More recently, a PCR-based genotyping tool has been developed and used to identify the different Giardia spp. present in environmental water [17]. This technique however can be prone to contamination and thus other alternative approaches are currently being explored. In particular, matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) has been used to identify and classify bacteria [6], viruses, as well as protozoan parasites [12,13], although this approach has not been applied to study Giardia spp.

This manuscript describes a MALDI-TOF MS based approach that is used to characterize the mass spectral fingerprints of intact Giardia lamblia and Giardia muris cysts. This study identified common mass spectral peaks shared by the two species as well as peaks specific to G. lamblia and G. muris, which are useful in differentiating the two organisms. Additional analyses revealed that the mass spectral profiles of intact cysts consisted partly of peaks representing trophozoite-derived proteins, based on comparison with purified trophozoites. These results suggest the potential application of intact cell MALDI-TOF mass spectrometry as an alternative high throughput approach for species identification of Giardia spp.


JOURNAL Chemically and Genetically Immunocompromised Mice Are Not More Susceptible Than Immunocompetent Mice to Infection With Cryptosporidium Muris 09/29/2006
MILLER, T., M. W. WARE, L. J. WYMER, AND F. W. SCHAEFER. Chemically and Genetically Immunocompromised Mice Are Not More Susceptible Than Immunocompetent Mice to Infection With Cryptosporidium Muris. L.S. Mansfield, S. Taylor (ed.), Veterinary Parasitology. Elsevier, Shannon, Ireland, 141(1/2):66-83, (2006).
Abstract: The prevailing paradigm is that immunosuppressed individuals are more susceptible to infection and are at higher risk of infection from Cryptosporidium oocysts if present in drinking water. To test this hypothesis, three immune conditions were examined: genetically immunocompromised T cell deficient CD-1 nude mice, B and T cells deficient Fox Chase CB-17/IcrClB SCID mice, and chemically immunosuppressed C57Bl/6 mice. Chemical immunosuppression was induced with a single subcutaneous injection of methylprednisolone acetate (MPA) at 600 mg/kg. The MPA immunosuppressed C57Bl/6 mice were characterized by a sustained decrease in circulating CD3, CD4 and CD8 T-lymphocytes of greater than 80 percent and a similar decrease in B-lymphocytes. A sharp rise in circulating mature segmented neutrophils followed MPA injection, dropping sharply after 10-14 days, mirroring the decrease in lymphocytes. The cessation of oocyst production after MPA was not accompanied by a radical rise in circulating CD3 or CD4 T-lymphocytes, but rather a rise in CD8 T-lymphocytes. The ID50 for the MPA immunosuppressed C57Bl/6 mice was 122 oocysts, whereas the ID50 for the C57Bl/6 immunocompetent group was 44. The genetically immunocompromised mice showed similar differences. The ID50 for CD-1 nude mice was 166 oocysts compared to 64 in CD-1 immunocompetent mice. For Fox Chase CB-17/IcrClB SCID and the immunocompetent CB-17 mice, the ID50's were 83 and 60 oocysts, respectively. These results suggest that the lack of an immune response does not increase the ability of C. muris to establish a productive infection and produce oocysts.

JOURNAL Reduction in Asthma Morbidity in Children as a Result of Home Remediation Aimed at Moisture Sources 08/01/2006
KERCSMER, C. M., D. G. DEARBORN, M. SCHLUCHTER, L. XUE, L. KIRCHNER, J. SOBOLEWSKI, S. J. GREENBERG, AND S. J. VESPER. Reduction in Asthma Morbidity in Children as a Result of Home Remediation Aimed at Moisture Sources. ENVIRONMENTAL HEALTH PERSPECTIVES. National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, 114(8):1574-1580, (2006).
Abstract: Objective: Home dampness, presence of mold and allergens have been associated with asthma morbidity. We examined changes in asthma morbidity in children as a result of home remediation aimed at moisture sources.
Design: Prospective, randomized controlled trial.

Participants: Symptomatic, asthmatic children (n=62), aged 2-17 years, living in a home with indoor mold.

Measurements: All participants received an asthma intervention including an action plan, education, and individualized problem solving. The remediation group received household repairs including reduction of water infiltration, removal of water damaged building materials, and HVAC alterations. The control group received only home cleaning information. We measured total and allergen-specific serum IgE, peripheral blood eosinophil counts, and urinary cotinine. Environmental dust samples were analyzed for dust mite, cockroach, rodent urinary protein, endotoxin and fungi. Follow-up period was for one year.

Results: Children in both groups showed improvement in asthma symptomatic days during the pre-remediation portion of the study. The remediation group had a significant decrease in symptom days (p=0.003, as randomized; p= 0.004, intent to treat) following remodeling while these parameters in the control group did not significantly change. In the post-remediation period, the remediation group had a lower rate of exacerbations compared to control asthmatics (1/29 vs. 11/33, respectively, p=0. 003, as-treated; 28.1% and 10.0% respectively, p=.11, intent to treat)

Conclusion: Construction remediation aimed at the root cause of moisture sources and combined with a medical/ behavioral intervention significantly reduces symptom days and health care utilization for asthmatic children who live in homes with a documented mold problem.


JOURNAL Fungal Speciation Using Quantitative Polymerase Chain Reaction (Qpcr) in Patients With and Without Chronic Rhinosinusitis 08/01/2006
MURR, A. W., A. N. GOLDBERG, AND S. J. VESPER. Fungal Speciation Using Quantitative Polymerase Chain Reaction (Qpcr) in Patients With and Without Chronic Rhinosinusitis. The Laryngoscope. Lippincott Williams & Wilkins, Philadelphia, PA, 116(8):1342-1348, (2006).
Abstract: Objectives/Hypothesis: 1. to determine the mycology of the middle meatus using an endoscopically guided brush sampling technique and polymerase chain reaction laboratory processing of nasal mucous. 2. To compare the mycology of the middle meatus in patients with sinus disease to subjects without sinus disease. 3. To compare the responses on two standardized quality of life survey forms between patients with and without sinusitis, and to determine whether the presence of fungi in the middle meatus impacts responses on these data sets.
Study Design: A prospective case-controlled study.

Methods: Patients with sinus disease and patients without sinus disease were enrolled in the study. A disease specific, validated Sinonasal Outcomes Test survey was completed by the subjects (SNOT-20) and a generalized validated Medical Outcomes Short Form 36 Survey (SF-36) was also completed. An endoscopically guided brush sampling of nasal mucous was obtained from the middle meatus. Fungal specific quantitative polymerase chain reaction (QPCR) was performed on the obtained sample to identify one of 82 different species of fungus in the laboratory. Statistical analysis was used to categorize the recovered fungal DNA and to cross reference this information with the outcomes surveys.

Results: The fungal recovery rate in the study was 45.9% in patients with sinus disease and 45.9% in control subjects. Patients with chronic rhinosinusitis (CRS) had a mean SNOT-20 score of 1.80 versus the control group mean score of 0.77 (P<.0001). SF-36 data similarly showed a statistically significant difference between diseased and control populations with controls scoring a mean of 80.37 and chronic rhinosinusitis patients scoring a mean of 69.35 for a P-value of .02. However, no statistical significance could be ascribed to the presence or absence of fungi recovered, the type of fungi recovered, or the possible impact of fungi on the quality of life survey results.

Conclusion: The recovery rate of fungi from the middle meatus of patients with and without chronic rhinosinusitis is 45.9% using QPCR techniques. No direct causation with regard to fungal species or presence was proven, however, a species grouping for future studies is proposed based upon trends in these data and other reports. Disease specific outcomes surveys revealed a statistically significant difference between the two patient groups.


JOURNAL Specific Molds Associated With Asthma in Water-Damaged Homes 08/01/2006
VESPER, S. J., C. MCKINSTRY, C. YANG, R. A. HAUGLAND, C. M. MCKERCSMAR, I. YIKE, M. D. SCHLUCHTER, L. KIRCHNER, J. SOBOLEWSKI, T. M. ALLAN, AND D. G. DEARBORN. Specific Molds Associated With Asthma in Water-Damaged Homes. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL MEDICINE. Lippincott Williams & Wilkins, Philadelphia, PA, 48(8):852-858, (2006).
Abstract: Objective: We sought to determine if specific molds were found in significantly higher concentrations in the water-damaged homes of asthmatic children compared to homes with no visible water damage. Methods: The mold concentrations in the dust in asthmatic children's bedrooms in water-damaged homes (N=60) and control homes (N=22) were measured by mold specific quantitative PCR (MSQPCR). Results: Two molds, Scopulariopsis brevicaulis and Trichoderma viride, had significantly (p < 0.05) higher concentrations in asthmatics homes compared to control homes and three other molds (Penicillium crustosum Group, Stachybotrys chartarum and Wallemia sebi) had p values < 0.1. Conclusions: A relative moldiness index© (RMI©) was developed to predict the likely development of asthma in water-damaged homes in Cleveland.

JOURNAL Transport of Chemical and Microbial Compounds from Known Wastewater Discharges: Potential for Use as Indicators of Human Fecal Contamination 07/15/2006
GLASSMEYER, S., E. FURLONG, D. KOLPING, M. MEYER, AND D. D. KRYAK. Transport of Chemical and Microbial Compounds from Known Wastewater Discharges: Potential for Use as Indicators of Human Fecal Contamination. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 39(14):5157-5169, (2005).
Abstract: The quality of drinking and recreational water currently (2005) is determined using indicator bacteria. However, the culture tests used to analyze for these bacteria require a long time to complete, and do not discriminate between human and animal fecal material sources. One complementary approach is to use chemicals found in human wastewater, which would have the advantages of (1) potentially shorter analysis times than the bacterial culture tests, and (2) being selected for human-source specificity. At ten locations, water samples were collected upstream and at two successive points downstream from a wastewaster treatment plant (WWTP); a treated effluent sample was also collected at each WWTP. This sampling plan was used to determine the persistence of a chemically diverse suite of emerging contaminants in streams. Samples also were collected at two reference locations assumed to have minimal human impacts. Of the 110 chemical analytes investigated in this project, 78 were detected at least once. The number of compounds in a given sample ranged from 3 at a reference location to 50 in a WWTP effluent sample. The total analyte load at each location varied from 0.018 µg/L at the reference location to 97.7 µg/L in a separate WWTP effluent sample. Although most compound concentrations were in the range of 0.01 to 1.0 µg/L, in some samples, individual concentrations were in the range of 5 to 38 µg/L. The concentrations of the majority of the chemicals present in the samples generally followed the expected trend: they were either nonexistent or at trace levels in the upstream samples, had their maximum concentrations in the WWTP effluent samples, and then declined in the two downstream samples. This research suggests that selected chemicals are useful as tracers of human wastewater discharge.

JOURNAL Ultrasonically Induced Degradation of Microcystin-Lr and-Rr: Identification of Products, Effects of Ph, Formation and Destruction of Peroxides 06/15/2006
SONG, W., A. A. DELACRUZ, K. REIN, AND K. E. O'SHEA. Ultrasonically Induced Degradation of Microcystin-Lr and-Rr: Identification of Products, Effects of Ph, Formation and Destruction of Peroxides. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 40(12):3941-3946, (2006).
Abstract: Microcystins (MCs) are a family of toxic peptides produced by a number of cyanobacteria commonly found in lakes, water reservoirs, and recreational facilities. The increased eutrophication of freshwater supplies has led to an increase in the incidence of cyanobacterial harmful algal blooms and concerns over the public health implications of these toxins in the water supply. Conventional water treatment methods are ineffective at removing low concentrations of cyanotoxins, hence specialized treatment is usually recommended for treatment of contaminated water. In this study, the products of ultrasonically induced degradation of microcystin-LR (MC-LR) and microcystin-RR (MC-RR) were analyzed by LC-MS to elucidate the probable pathways of degradation of these toxins. Results indicate preliminary products of sonolysis of MCs are due to the hydroxyl radical attack on the benzene ring and diene of the Adda peptide residue and cleavage of the Mdha-Ala peptide bond. The effect of pH on the toxin degradation was evaluated since the pH of the solution changes upon ultrasonic irradiation and varies with the water quality of treatable waters. The initial rate of MC-LR degradation is greater at acidic pH and coincides with the change in hydrophobic character of MC-LR as a function of pH. Hydrogen and organic peroxides are formed during ultrasonic irradiation, but can be eliminated by adding Fe(II). The addition of Fe(II) also accelerates the degradation of MC-LR, presumably by promoting the formation of hydroxyl radicals via conversion of ultrasonically produced H2O2. These findings suggest that sonolysis can effectively degrade MCs in drinking water.

JOURNAL Microbes, Monitoring and Human Health 06/01/2006
DUFOUR, A. P. AND L. J. WYMER. Microbes, Monitoring and Human Health. OCEANOGRAPHY. Oceanography Society, Rockville, MD, 19(2):72-80, (2006).
Abstract: There are about 20,000 wastewater treatment plants in the United States. These plants discharge about 50 trillion gallons of wastewater daily into the nation's surface waters. Most wastewater contains human feces, which are a potential source of microbial pathogens. Pathogens that may be found in the sewage include bacteria, viruses, and protozoa. All of these microorganisms are transmitted via the fecal-oral route; therefore, if wastewater is discharged to surface waters, they pose a health risk to anyone who comes in contact with the water or who consumes food harvested from the water. The potential risks that are associated with wastewater make disposal and control of wastewater a significant public health issue.

JOURNAL Comparison of Multiple Point and Composite Sampling for the Purpose of Monitoring Bathing Water Quality 06/01/2006
KINZELMAN, J. L., A. P. DUFOUR, L. J. WYMER, G. REES, K. R. POND, AND R. C. BAGLEY. Comparison of Multiple Point and Composite Sampling for the Purpose of Monitoring Bathing Water Quality. LAKE AND RESERVOIR MANAGEMENT. North American Lake Management Society, Madison, WI, 22(2):95-102, (2006).
Abstract: The USEPA Beaches Environmental Assessment and Coastal Health Act (BEACH Act) requires states to develop monitoring and notification programs for recreational waters using approved bacterial indicators. Implementation of an appropriate monitoring program can, under some circumstances, be expensive. This study explored the use of composite sampling at two Racine, WI beaches over a four month period (n = 68 days) in order to determine whether compositing can provide a valid, unbiased, and cost-effective measure of water quality. Multiple point sampling occurred throughout the bathing season with water samples collected daily from three or four fixed locations along each beach. From each individual sample, well-mixed aliquots were combined to form a composite sample. Individual and composite samples were assayed identically for Escherichia coli using Colilert-18 and Quanti-Tray 2000 (IDEXX Laboratories, Inc., Westbrook, ME). Results from this study indicate a reasonable expectation of a simple 1:1 ratio between the composite samples and the arithmetic mean of the individual samples. Additionally, log variance of the composite sample results did not differ significantly from that of the single sample averages (p > 0.2). Empirical values for log standard deviations varied by no more than 7% between the composite sample and individually assayed samples. Thus compositing, as performed in this study, appears to introduce neither bias nor additional variability into the monitoring results and stands as a reasonable alternative to data sets derived from single-sample methods. Regulatory programs adopting this approach could maintain sample integrity while reducing the costs associated with recreational water quality assessment.

JOURNAL Water Ingestion During Swimming Activities in a Pool: A Pilot Study 06/01/2006
DUFOUR, A. P., O. M. EVANS, AND T. D. BEHYMER. Water Ingestion During Swimming Activities in a Pool: A Pilot Study. JOURNAL OF WATER AND HEALTH. IWA Publishing, London, Uk, 4(4):425-430, (2006).
Abstract: Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized. This fact was used to determine the amount of water swallowed during swimming activity. Fifty-three recreational swimmers, using a community swimming pool disinfected with cyanuric acid stabilized chlorine, participated in the study. The participants did not swim on the day before or after the test swim. The swimmers were asked to actively swim for at least 45 minutes and to collect their urine for the next 24 hours. Cyanuric acid was measured in pool water using high performance liquid chromatography and porous graphitic carbon columns with UV detection. The urine sample assay required a clean-up procedure to remove urinary proteins and interfering substances. Results of the study indicate that non-adults ingest about twice as much water as adults during swimming activity. The average amount of water swallowed by non-adults and adults was 37 ml and 16 ml, respectively. The designater and human urine were effective for measuring the volume of water swallowed during swimming activity.

JOURNAL The Role of Flushing Dental Waterlines for the Removal of Microbial Contaminants Mceard 05/01/2006
RICE, E. W., W. K. Rich, C. H. JOHNSON, AND D. J. LYE. The Role of Flushing Dental Waterlines for the Removal of Microbial Contaminants Mceard. PUBLIC HEALTH REPORTS. Elsevier Science Ltd, New York, NY, 121(3):120-121, (2006).
Abstract: Objectives. This study was designed to determine the role of flushing dental water lines for the removal of heterotrophic plate count bacteria, Legionella spp., and free-living protozoa. Methods. Forty dental offices were surveyed in the study. An initial sample and a sample taken after three minutes of flushing were obtained from the air/water syringe at each location. All samples were quantitatively analyzed for heterotrophic bacteria using three bacteriological procedures. The samples were analyzed for the presence of Legionella spp. using cultural, immunological, and molecular procedures and for the occurrence of free-living protozoa using a killed bacteria plate procedure. Results. The flushing process reduced the level of heterotrophic plate count bacteria by 1.1 to 1.5 log10 CFU/ml. Compliance with recommendations for bacterial levels varied depending on the methodology employed in the analysis. The flushing process did not reduce the occurrence of Legionella spp. or free-living protozoa. Conclusion. The results support recent U.S. Centers for Disease Control and Prevention recommendations that the process of flushing dental water lines cannot be relied upon as a sole means of reliably improving the quality of water used in dental treatment.

JOURNAL Developing the Ermi © "EPA Relative Moldiness Index" Based on Mold-Specific Quantitative Pcr (Msqpcr) 04/05/2006
VESPER, S. J. Developing the Ermi © "EPA Relative Moldiness Index" Based on Mold-Specific Quantitative Pcr (Msqpcr). SYNERGIST. American Industrial Hygiene Association, 39-43, (2006).
Abstract: Improving indoor air quality has been a priority at the US EPA for many years. Among the components of indoor air, molds present a growing concern for the public. A primary information source on indoor molds is the news media, which often confuses rather than clarifies the situation. In addition, mold experts have failed to reach a consensus on sampling methods and the interpretation of analytical data obtained in a typical mold inspection.
EPA guidance is available to help the American public understand indoor mold issues (http://www.epa.gov/mold and www.epa.gov/iaq). In addition, US EPA scientists developed Mold Specific Quantitative PCR (MSQPCR) to identify and quantify molds in various matrices. This new technology, now licensed by many companies in the US and EU (http://www.epa.gov/microbes/moldtech.htm), is available today for use by industrial hygienists performing microbial inspections and assessments. The EPA is currently collecting data to develop ERMI©, the EPA Relative Moldiness Index which is based on the use of this technology and employed as a measure of the amounts and types of mold species present in household dust.

JOURNAL Method Development for the Analysis of N-Nitrosodimethylamine and Other N-Nitrosamines in Drinking Water at Low Nanogram/Liter Concentrations Using Solid Phase Extraction and Gas Chromatography With Chemical Ionization Tandem Mass Spectrometry 03/31/2006
MUNCH, J. W. AND M. BASSETT. Method Development for the Analysis of N-Nitrosodimethylamine and Other N-Nitrosamines in Drinking Water at Low Nanogram/Liter Concentrations Using Solid Phase Extraction and Gas Chromatography With Chemical Ionization Tandem Mass Spectrometry. JOURNAL OF AOAC INTERNATIONAL. AOAC International, Gaithersburg, MD, 89(2):486-497, (2006).
Abstract: N-Nitrosodimethylamine (NDMA) is a probable human carcinogen that has been identified as a drinking water contaminant of concern. United States Environmental Protection Agency (USEPA) Method 521 has been developed for the analysis of NDMA and six additional N-nitrosamines in drinking water at low ng/L concentrations.

JOURNAL In Vitro Biotransfomation of An Arsenosugar By Mouse Anaerobic Cecal Microflora and Cecal Tissue Examined Using Ic-ICP-MS and LC-Esi-MS/MS 03/09/2006
CONKLIN, S., P. A. CREED, AND JOHN T. CREED. In Vitro Biotransfomation of An Arsenosugar By Mouse Anaerobic Cecal Microflora and Cecal Tissue Examined Using Ic-ICP-MS and LC-Esi-MS/MS. ANALYST. Royal Society of Chemistry, Cambridge, Uk, 131(5):648-655, (2006).
Abstract: This investigation examined chemical and microbiological transformations of an arsenosugar by mouse cecum. To mimic the low oxygen environment in the mammalian gastrointestinal tract, reaction mixtures were incubated under anaerobic conditions. An arsenosugar extracted from ribbon kelp, 3-[5-deoxy-5-(dimethylarsinoyl)-ß-ribofuranosyloxy-2-hydroxypropanesulfonic acid, As(392), was added to reaction mixtures that contained either cecal microflora or cecal tissue homogenate. These reaction mixtures were incubated at 0 or 37°C for up to 48 hours to monitor biotransformation of the arsenosugar. Analysis of the reaction mixtures by IC-ICP-MS and LC-ESI-MS/MS indicated that the arsenosugar was converted primarily (95%) to its sulfur analog in less than 1 h at 37°C. Conversion of As(392) to its sulfur analog was much slower at 0°C (21% conversion after 48 h). In reaction mixtures with cecal tissue homogenate, conversion of As(392) to its sulfur analog was slower (77% conversion after 48 h at 37°C). A good mass balance was found in all reaction mixtures between the amount of arsenosugar added and the sum of all detected arsenic-containing products. LC-ESI-MS/MS spectra of the sulfur-containing arsenosugar formed in all reaction mixtures containing cecal microflora compared well with those of a synthetic standard. These results suggest that the anaerobic microflora of the gastrointestinal tract can rapidly convert ingested arsenosugars to sulfur analogs. This biotransformation may affect the subsequent absorption, metabolism, and disposition of arsenic present in arsenosugars.This investigation examined chemical and microbiological transformations of an arsenosugar by mouse cecum. To mimic the low oxygen environment in the mammalian gastrointestinal tract, reaction mixtures were incubated under anaerobic conditions. An arsenosugar extracted from ribbon kelp, 3-[5-deoxy-5-(dimethylarsinoyl)-ß-ribofuranosyloxy-2-hydroxypropanesulfonic acid, As(392), was added to reaction mixtures that contained either cecal microflora or cecal tissue homogenate. These reaction mixtures were incubated at 0 or 37°C for up to 48 hours to monitor biotransformation of the arsenosugar. Analysis of the reaction mixtures by IC-ICP-MS and LC-ESI-MS/MS indicated that the arsenosugar was converted primarily (95%) to its sulfur analog in less than 1 h at 37°C. Conversion of As(392) to its sulfur analog was much slower at 0°C (21% conversion after 48 h). In reaction mixtures with cecal tissue homogenate, conversion of As(392) to its sulfur analog was slower (77% conversion after 48 h at 37°C). A good mass balance was found in all reaction mixtures between the amount of arsenosugar added and the sum of all detected arsenic-containing products. LC-ESI-MS/MS spectra of the sulfur-containing arsenosugar formed in all reaction mixtures containing cecal microflora compared well with those of a synthetic standard. These results suggest that the anaerobic microflora of the gastrointestinal tract can rapidly convert ingested arsenosugars to sulfur analogs. This biotransformation may affect the subsequent absorption, metabolism, and disposition of arsenic present in arsenosugars.

JOURNAL Isolation of the Genome Sequence Strain Mycobacterium Avium 104 from Multiple Patients Over a 17-Year Period 03/01/2006
HORAN, K. L., R. FREEMAN, K. WEIGEL, M. SEMRET, S. L. PFALLER, T. C. COVERT, D. V. SOOLINGEN, S. C. LEAO, M. A. BEHR, AND G. A. CANGELOSI. Isolation of the Genome Sequence Strain Mycobacterium Avium 104 from Multiple Patients Over a 17-Year Period. JOURNAL OF CLINICAL MICROBIOLOGY. American Society for Microbiology, Washington, DC, 44(3):783-789, (2006).
Abstract: The genome sequence strain 104 of the opportunistic pathogen Mycobacterium avium was isolated form an adult AIDS patient in Southern California in 1983. Isolates of non-paratuberculosis M. avium from 207 other patients in Southern California and elsewhere were examined for genotypic identity to strain 104. This process was facilitated by the use of a novel two-step approach. In the first step, all 208 strains in the sample were subjected to a high throughput, large sequence polymorphism (LSP) based genotyping test, in which DNA form each strain was tested by PCR for the presence or absence of 4 hypervarible genomic regions. Nineteen isolates exhibited an LSP type that resembled that of strain 104. this subset of 19 isolates was then to a high resolution repetitive sequence based PCR typing which identified 10 isolates within the subset that were genotypically identical to strain 104. These isolates came from 10 different patients at 5 clinical sites in the western United States and they were isolated over a 17 year time span. Therefore the sequenced genome of M. avium, strain has been associated with disease in multiple patients in the western United States. Although M. avium is known for its genetic plasticity these observations also show that strains of the pathogen can be genotypically stable over extended time periods.

JOURNAL Nigerlysintm, Hemolysin Produced By Aspergillus Niger, Causes Lethality of Primary Rat Cortical Neuronal Cells in Vitro 02/15/2006
DONOHUE, M. J., W. WEI, J. WU, N. H. ZAWIA, N. HUD, V. DE JESUS, D. SCHMECHEL, J. M. HETTICK, D. H. BEEZHOLD, AND S. J. VESPER. Nigerlysintm, Hemolysin Produced By Aspergillus Niger, Causes Lethality of Primary Rat Cortical Neuronal Cells in Vitro. TOXICOLOGY. Elsevier Science Ltd, New York, NY, 219:150-155, (2006).
Abstract: Aspergillus niger produced a proteinaceous hemolysin, nigerlysinTM when incubated on sheep's blood agar at both 23° C and 37°C. Nigerlysin was purified from tryptic soy broth culture filtrate. Purified nigerlysin has a molecular weight of approximately 72 kDa, with an isoelectric point of 3.45. Nigerlysin is heat stable up to 65° C but unstable at 75° C when incubated for 10 min. Circular dichroic analysis revealed that nigerlysin has an alpha helical structure. Exposure of primary rat cortical neuronal cells showed a threshold of toxicity between 2 and 5 ng. Exposure to 10 ng of nigerlysin resulted in the rapid loss of their viability, approximately 50% in 24 h.

JOURNAL Urban Contributions of Glysphosate and Its Degradate Ampa to Streams in the United States 02/01/2006
KOLPIN, D. W., M. THURMAN, E. A. LEE, M. T. MEYER, E. T. FURLONG, AND S. GLASSMEYER. Urban Contributions of Glysphosate and Its Degradate Ampa to Streams in the United States. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier Science Ltd, New York, NY, 354(2-3):191-197, (2006).
Abstract: Glyphosate is the most widely used herbicide in the world, being routinely applied to control weeds in both agricultural and urban settings. Microbial degradation of glyphosate produces aminomethyl phosphonic acid (AMPA). The high polarity and water-solubility of glyphosate and AMPA has, until recently, made their analysis in water samples problematic. Thus, compared to other herbicides (e.g. atrazine) there are relatively few studies on the environmental occurrence of glyphosate and AMPA. In 2002, treated effluent samples were collected from 10 wastewater treatment plants (WWTPs) to study the occurrence of glyphosate and AMPA. Stream samples were collected upstream and downstream of the 10 WWTPs. Two reference streams were also sampled. The results document the apparent contribution of WWTP effluent to stream concentrations of glyphosate and AMPA, with roughly a two-fold increase in their frequencies of detection between stream samples collected upstream and those collected downstream of the WWTPs. Thus, urban use of glyphosate contributes to glyphosate and AMPA concentrations in streams in the United States. Overall, AMPA was detected much more frequently (67.5%) compared to glyphosate (17.5%).

JOURNAL Can Rapid Measures of Recreational Water Quality Predict Swimming Associated Gastrointestinal Illness? 01/01/2006
WADE, T. J., R. L. CALDERON, E. A. SAMS, M. BEACH, K. P. BRENNER, A. H. WILLIAMS, AND A. P. DUFOUR. Can Rapid Measures of Recreational Water Quality Predict Swimming Associated Gastrointestinal Illness? ENVIRONMENTAL HEALTH PERSPECTIVES. National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, 114(1):24-28, (2004).
Abstract: Standard methods to measure recreational water quality require at least 24 hours to obtain results making it impossible to assess the quality of water within a single day. Methods to measure recreational water quality in two hours or less have been developed. Application of rapid methods could give considerably more accurate and timely assessments of recreational water quality. A prospective study of beach-goers was conducted at two Great Lakes beaches to examine the association between recreational water quality, obtained using rapid methods, and gastrointestinal (GI) illness following swimming. Beach-goers were asked about swimming and other beach activities and ten to twelve days later were asked about the occurrence of gastrointestinal symptoms. Water samples were tested for Enterococci and Bacteroides using the quantitative polymerase chain reaction method. Significant trends between increased GI illness and Enterococci were observed at the Lake Michigan beach, and a positive trend was observed for Enterococci at the Lake Erie beach. The association remained significant for Enterococci when the two beaches were combined. A positive trend was observed for Bacteroides at the Lake Erie beach, but no trend was observed at the Lake Michigan beach. Enterococci samples collected at 8:00 am were predictive of gastrointestinal illness that day. The association between Enterococci and illness strengthened as time spent swimming in the water increased. This is the first study to show that water quality measured by rapid methods can predict swimming-associated health effects.

JOURNAL Development of Method 535 for the Determination of Chloroacetanilide and Other Acetamide Herbicide Degradates in Drinking Water By Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry 01/01/2006
SHOEMAKER, J. A. AND M. BASSETT. Development of Method 535 for the Determination of Chloroacetanilide and Other Acetamide Herbicide Degradates in Drinking Water By Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry. JOURNAL OF AOAC INTERNATIONAL. AOAC International, Gaithersburg, MD, 89(1):201-209, (2006).
Abstract: EPA Method 535 has been developed in order to provide a method for the analysis of "Alachlor ESA and other acetanilide degradation products" which are listed on U.S. EPA's 1998 Drinking Water Contaminant Candidate List. Method 535 uses solid phase extraction with a nonporous graphitized carbon sorbent to extract the ethane sulfonic acid (ESA) and oxanilic acid (OA) degradates of propachlor, flufenacet, dimethenamid, alachlor, acetochlor and metolachlor from finished drinking water matrices. Separation and quantitation of the target analytes are achieved with liquid chromatography/tandem mass spectrometry (LC/MS/MS). Dimethachlor ESA and butachlor ESA were chosen during the method development as the surrogate and internal standard. Drinking water samples were dechlorinated with ammonium chloride without adversely affecting the analyte recoveries. Typical mean recoveries of 92-116% in deionized water and 89-116% in ground water were observed with relative standard deviations of <5%.

JOURNAL Statistical Procedures for Determination and Verification of Minimum Reporting Levels for Drinking Water Methods 01/01/2006
WINSLOW, S., B. PEPICH, J. J. MARTIN, G. R. HALLBERG, D. J. MUNCH, C. FREBIS, E. J. HEDRICK, AND R. A. KROP. Statistical Procedures for Determination and Verification of Minimum Reporting Levels for Drinking Water Methods. ENVIRONMENTAL SCIENCE AND TECHNOLOGY. John Wiley & Sons, Ltd., Indianapolis, IN, 40(1):281-288, (2006).
Abstract: The United States Environmental Protection Agency's (EPA) Office of Ground Water and Drinking Water (OGWDW) has developed a single-laboratory quantitation procedure: the lowest concentration minimum reporting level (LCMRL). The LCMRL is the lowest true concentration for which future recovery is predicted to fall with high confidence (99%) between 50 and 150% recovery. The procedure takes into account the precision and accuracy. Multiple concentration replicate data are processed through the entire analytical method and are plotted as measured sample concentration (y-axis) versus true concentration (x-axis). If the data supports an assumption of constant variance over the concentration range, an ordinary least squares regression line is drawn; otherwise a variance weighted least squares is used. Prediction interval lines of 99 % confidence are drawn about the regression. At the points where the prediction interval lines intersect with data quality objective lines of 50 and 150% recovery, lines are dropped to the x-axis. The higher of the two values is the LCMRL. The LCMRL procedure is flexible because the data quality objectives (50 to 150%) and the prediction interval confidence (99%) can be varied to suit program needs. The LCMRL determination is performed during method development only. A simpler procedure for verification of data quality objectives at a given minium reporting level (MRL) is also presented. The verification procedure requires a single set of seven samples taken through the entire method procedure. If the calculated prediction interval is contained within data quality recovery limits (50 to 150%), the lab performance at the MRL is verified.

PRESENTATION An Observational Study: Determination of the Volume of Water Ingested During Recreational Swimming Activities 12/07/2006
EVANS, O. M., L. J. WYMER, T. D. BEHYMER, AND A. P. DUFOUR. An Observational Study: Determination of the Volume of Water Ingested During Recreational Swimming Activities. Presented at National Beaches Conference, Niagra Falls, NY, October 10 - 13, 2006.
Abstract: EPA's Action Plan for Beaches and Recreational Waters describes research needs for exposure assessment related to swimming activities such as characterizing swimming populations with regard to routes and magnitudes of exposure. This includes characteristics such as the duration of time in the water, how much water is swallowed and frequency of swimming-related activities. The results from three epidemiological studies that examined the relationship between swimming-associated illness and water quality have shown that illness in children occurs at a higher rate than in adults. These differences may be the result of immature immune systems in children or differences in behavior during swimming activities. The current study examined water ingestion by swimmers in a swimming pool. Outdoor swimming pools use cyanuric acid to stabilize chlorine. Cyanuric acid is not absorbed through the skin, and if swallowed, passes through the body un-metabolized. The amount of water ingested can be calculated if the cyanuric acid concentration is known in the pool water and in a 24 hour urine specimen. About 570 individuals participated in the study, and swam at least an hour, and subsequently collected their urine over a 24 hour period. The results of the study showed that children ingested nearly twice as much water as adults. Children swallowed, on the average, about 47 ml of water per swim period, whereas adults ingested about 24 ml of water per swim period. Adult males ingested significantly more water than females, 30 ml and 19 ml, respectively. The results of this study provide the first empirical evidence of the amount of water individuals swallow during recreational swimming activities.

PRESENTATION The Total Coliform Rule and Future of the Indicators and Pathogens in Drinking Water Assessment 11/27/2006
OSHIMA, K. The Total Coliform Rule and Future of the Indicators and Pathogens in Drinking Water Assessment. Presented at Florida Section of the American Water Works Association Workshop 1B Emerging Pathogens of Regulatory Significance, Orlando, FL, November 27, 2006.
Abstract: This presentation describes some of the major microbiological issues related to drinking water quality of concern to the EPA. The revision process of the Total Coliform Rule and the selection of the Microbial Contaminant List (CCL) are discussed. A brief overview of research conducted in the Microbiological and Chemical Exposure Research Division of the National Exposure Research Laboratory that is focused on the occurrence and virulence for microbial agents that are on the current CCL list are also described.

PRESENTATION Comparison of the Relative Efficacy of Secondary Biological Treatment and Disinfection at Removing Emerging Contaminants from Wastewater 11/05/2006
GLASSMEYER, S., D. W. KOLPIN, AND E. T. FURLONG. Comparison of the Relative Efficacy of Secondary Biological Treatment and Disinfection at Removing Emerging Contaminants from Wastewater. Presented at Society of Environmental Toxicology and Chemistry Meeting, Montreal, QC, CANADA, November 05 - 09, 2006.
Abstract: This slide presentation was presented at the Society for Environemental Toxicology Meeting, Quebec, Montreal, Canada, November 5-9, 2006

PRESENTATION Development of An EPA Method for Perfluoroalkyl Compounds in Drinking Water 11/05/2006
SHOEMAKER, J. A. Development of An EPA Method for Perfluoroalkyl Compounds in Drinking Water. Presented at Water Quality Technology Conference, Denver, CO, November 05 - 09, 2006.
Abstract: Over the past five years, perfluoroalkyl compounds (PFCs) in water have become an emerging environmental issue. This research focuses on the development of an analytical method for the determination of perfluoroalkyl compounds in drinking water to be used by EPA's Office of Ground Water and Drinking Water for the potential future collection of nationwide occurrence data. Drinking water samples are concentrated by solid phase extraction and analyzed using liquid chromatography/tandem mass spectrometry. Preliminary recovery data were obtained for 16 out of 17 targeted (PFCs). For reagent water fortified at 25 ng/L, recoveries ranged from 70 to 103% with a relative standard deviation of 2-10%.

PRESENTATION Analysis of 1,4-Dioxane and Other Water Soluble Volatile Organic Compounds By Solid Phase Extraction and Gc/MS 11/05/2006
MUNCH, J. W. Analysis of 1,4-Dioxane and Other Water Soluble Volatile Organic Compounds By Solid Phase Extraction and Gc/MS. Presented at American Water Works Association Water Quality Technology Conference, Denver, CO, November 05 - 09, 2006.
Abstract: 1,4-Dioxane is emerging as a drinking water contaminant of concern. Because of its volatility and water solubility, 1,4-dioxane is difficult to extract and and concentrate from aqueous matrices. Because 1,4-dioxane is under consideration for the next drinking water Contaminant Candidate List, USEPA's National Exposure Research Laboratory is investigating new techniques for measuring it and other water soluble volatiles in drinking water. Solid phase extraction using coconut charcoal as the solid sorbent, and dichloromethane as the eluent, has shown promise for the extraction and concentration of 1,4-dioxane, as well as other water soluble volatile organic chemicals, from water matrices. Extracts were analyzed by GC/MS with large volume injection. Preliminary data for 1,4-dioxane demonstrate recovery from both reagent and tap water at 89.5 and 95.3%, respectively, with relative standard deviations (RSDs) less than 6.3%. Preliminary data for four additional water soluble volatiles, 1,2-butylene oxide, 1,3-dioxolane, t-butanol, and epichlorohydrin, demonstrate 92.5-114% recovery with RSDs less than 5.1%.

PRESENTATION Sub-Ppb Quantitation and Confirmation of Perchlorate in Drinking Waters Containing High Total Dissolved Solids Using Ion Chromatography With Mass Spectrometric Detection 11/02/2006
Hedrick, E J. AND D. J. Munch. Sub-Ppb Quantitation and Confirmation of Perchlorate in Drinking Waters Containing High Total Dissolved Solids Using Ion Chromatography With Mass Spectrometric Detection. Presented at American Water Works Association Water Quality Technology Conference, Philadelphia, PA, November 02 - 06, 2003.
Abstract: Perchlorate (ClO4 -) is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag inflators, and in highway safety flares. Based on EPA Information Request Responses and occurrence monitoring, there have been 95 confirmed ClO4 - releases in 25 states and 230 users or manufacturers in 40 states. From accidental releases and improper disposal practices of the past, ClO4 - has become a contaminant in surface and ground waters where it is highly mobile and, due to its chemical stability, persists for decades. The primary human health effect is inhibition of iodide uptake by the thyroid gland. By disrupting thyroid hormone production, ClO4 - interferes with metabolism and can affect brain development in fetuses and children, leading to mental impairment. There is now a need for a method that can confirm and quantify ClO4 - at concentrations lower than what is achievable using ion chromatography with suppressed conductivity detection. Coupled with ion chromatographic separation, mass spectrometry is by far the most promising analytical tool available today for low-level identification and quantitation of ClO4 - in drinking water. In this work, sub-ppb quantitation of ClO4 - in drinking waters using ion chromatography electrospray ionization mass spectrometry (IC-ESI-MS) is demonstrated.
The primary mass of interest for ClO4 - is 99 based on the 75.77% relative abundance of the chlorine-35 isotope. Mass 101 is a secondary mass of interest based on the 24.23% abundance of chlorine-37. In this work we demonstrate the feasibility of using oxygen-18 enriched perchlorate as an internal standard. The greatest benefit of such an internal standard is for the improvement of accuracy in the determination of perchlorate in waters with high total dissolved solids such as sulfate, carbonate and chloride. In the event that ClO4 - is regulated in drinking water or that a second national occurrence survey is conducted, this research will lead to an inherently more specific and sensitive U.S. EPA method than is currently available.

PRESENTATION Detection and Quantification of a Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interation of Arsenosugars With Sulfide 10/27/2006
CONKLIN, S., P. A. CREED, AND JOHN T. CREED. Detection and Quantification of a Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interation of Arsenosugars With Sulfide. Presented at The 26th Ralph & Helen Oesper Banquet, Poster Session and Symposium, Cincinnati, OH, October 27 - 28, 2006.
Abstract: It has been found that strong-base extraction of marine mollusks liberates between 0.5-2 ppm sulfide along with arsenicals including arsenosugars. Results will be presented indicating that at a pH of 12, the sulfide is present as S2- and is unlikely to react with the arsenosugar oxide to produce the arsenosugar sulfide. However, acidification of these extracts converts S2- to H2S, which reacts with the arsenosugar oxide and accounts for the conversion to the arsenosugar sulfide observed upon extraction acidification. These results are significant in that extraction procedures which liberate both sulfide and arsenosugars from seafood samples are likely to produce enhanced arsenosugar sulfides if the pH is not adjusted basic to minimize the production of H2S.

PRESENTATION Evaluation of Matrix Effects from Nationwide Inland Surface Waters on Quantitation Polymerase Chain Reaction Analysis for Fecal Indicator Bacteria 10/11/2006
HAUGLAND, R. A., S. SIEFRING, M. VARMA, E. ATIKOVIC, K. P. BRENNER, A. P. DUFOUR, AND L. J. WYMER. Evaluation of Matrix Effects from Nationwide Inland Surface Waters on Quantitation Polymerase Chain Reaction Analysis for Fecal Indicator Bacteria. Presented at National Beaches Conference, Niagra Falls, NY, October 11 - 13, 2006.
Abstract: This presentation was given at the National Beaches Conference, Niagra Falls, NY, October 11-13, 2006

PRESENTATION Utility of Pharmaceuticals and Other Emerging Contaminants as Chemical Indicators of Human Fecal Contamination 10/11/2006
GLASSMEYER, S., E. FURLONG, D. KOLPIN, K. P. BRENNER, T. WADE, E. SAMS, R. L. CALDERON, A. P. DUFOUR, AND M. BEACH. Utility of Pharmaceuticals and Other Emerging Contaminants as Chemical Indicators of Human Fecal Contamination. Presented at EPA's National Beaches Conference, Niagra Falls, NY, October 11 - 13, 2006.
Abstract: This poster was presented at the EPA's National Beaches Conference, Niagra Falls, NY, October 11-13, 2006

PRESENTATION Synthesis, Isolation and Characterization of Pentavalent Thioarsenical Standards 10/10/2006
FRICKE, M., S. YATHAVAKILLA, S. CONKLIN, P. A. CREED, C. A. SCHWEGEL, AND JOHN T. CREED. Synthesis, Isolation and Characterization of Pentavalent Thioarsenical Standards. Presented at 7th International Conference of Environmental and Biological Aspects of Main Group Organometallics , Heraklion, GREECE, October 10 - 12, 2006.
Abstract: This slide presentation was given at the 7th International Conference of Environmental and Biological Aspects of Main-Group Organometallics.

PRESENTATION Dietary Arsenic Exposure Assessment Using Enzymatic Based Extraction Conditions and Detection of Urinary Thio-Arsenicals as Metabolites of Exposure 10/10/2006
CREED, JOHN T., P. A. CREED, S. YATHAVAKILLA, S. CONKLIN, AND C. GALLAWA. Dietary Arsenic Exposure Assessment Using Enzymatic Based Extraction Conditions and Detection of Urinary Thio-Arsenicals as Metabolites of Exposure. Presented at 7th International Conference of Environmental and Biological Aspects of Main-Group Organometallics, Heraklion, GREECE, October 10 - 12, 2006.
Abstract: This slide presentation was given at the 7th International Conference of Environmental and Biological Aspects of Main-Group Organometallics, Heraklion, Crete, Greece, October 10-12, 2006

PRESENTATION Comparison of Illness Endpoints in Swimmers' Health Studies 10/10/2006
WYMER, L. J., A. P. DUFOUR, R. A. HAUGLAND, K. P. BRENNER, R. L. CALDERON, T. J. WADE, E. A. SAMS, AND M. BEACH. Comparison of Illness Endpoints in Swimmers' Health Studies. Presented at National Beaches Conference, Niagra Falls, NY, October 10 - 12, 2006.
Abstract: Prospective epidemiological studies on swimmers¿ health that were conducted by the U.S. Environmental Protection Agency (U.S. EPA) between 1973 and 1980 defined highly credible gastrointestinal illness (HCGI) as the occurrence of one or more of the following set of symptoms: (1) vomiting, (2) diarrhea with a fever or with a disabling condition (remaining home, in bed, or seeking medical attention), or (3) stomachache or nausea accompanied by a fever. Results of the HCGI endpoints from these studies were incorporated into health-based criteria for indicator bacteria in recreational waters. This definition of HCGI comprised a highly credible set of symptoms with minimal subjectivity involved in determining whether test subjects were actually ill or not. The National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, conducted by the U.S. EPA to evaluate rapid methods for determining fecal pollution, used a less strict definition for gastrointestinal illness (GI-NEEAR) that removed any requirement for fever. This is consistent with illness definitions used by the Centers for Disease Control and Prevention and others. Sufficient data were collected in the NEEAR study to enable comparison of the relative occurrences of GI-NEEAR, HCGI, and other illness endpoints. Comparisons of illness rates defined by these two case definitions, as well as by case definitions employed in the United Kingdom, Netherlands, and Germany, indicate that a constant relative risk adequately describes the relationship of the incidences between any two different illness endpoints. In addition, ordinal logistic regression was used to compare relative rates of HCGI and GI-NEEAR among all swimmers and non-swimmers. This indicates the validity of the proportional odds assumption that the relative effect of swimming exposure for either HCGI or GI-NEEAR is approximately the same.

PRESENTATION Identifying Chemical Compounds from Wastewater Discharges 10/10/2006
GLASSMEYER, S., E. T. FURLONG, AND D. W. KOLPIN. Identifying Chemical Compounds from Wastewater Discharges. Presented at Pharmaceutical in the Environment, Cincinnati, OH, October 10, 2006.
Abstract: This slide presentation was given at the Pharmaceuticals in the Environment, October 10, 2006

PRESENTATION Exposure Assessment Considerations in Utilizing Convential Chemical and Physiological Based Extraction Techniques Prior to to Arsenic Speciation 09/24/2006
CREED, JOHN T., P. A. CREED, C. GALLAWA, A. YOUNG, AND C. A. SCHWEGEL. Exposure Assessment Considerations in Utilizing Convential Chemical and Physiological Based Extraction Techniques Prior to to Arsenic Speciation. Presented at FACSS Meeting, Orlando, FL, September 24 - 28, 2006.
Abstract: This presentation was given at the FACSS Meeting in Orlando, FL, September 24-28, 2006

PRESENTATION How Much Water Do Swimmers Drink? 09/19/2006
EVANS, O. M., L. J. WYMER, T. D. BEHYMER, AND A. P. DUFOUR. How Much Water Do Swimmers Drink? Presented at World Aquatic Health Conference, Austin, TX, September 19 - 21, 2006.
Abstract: This abstract was presented at the World Aquatic Health Conference, Austin, TX, September 19-21, 2006.

PRESENTATION Enhancing in Vitro Infections of Cryptosporidium Parvum 09/10/2006
VARUGHESE, E. AND L. F. VILLEGAS. Enhancing in Vitro Infections of Cryptosporidium Parvum. Presented at 2006 WoodsHole Molecular Meeting, WoodsHole, MD, September 10 - 14, 2006.
Abstract: This poster was presented at the 2006 WoodsHole Molecular Meeting in WoodsHole, MA, September 10-14, 2006.

PRESENTATION Surfactant Templated Sol-Gel Synthesis of Mesoporous Tio2 Photocatalysts and Their Application in the Destruction of Cyanobacterial Toxins 09/10/2006
CHOI, H., M. G. ANTONIOU, A. A. DELACRUZ, J. A. SHOEMAKER, AND D. D. DIONYSIOU. Surfactant Templated Sol-Gel Synthesis of Mesoporous Tio2 Photocatalysts and Their Application in the Destruction of Cyanobacterial Toxins. Presented at 232th American Chemical Society National Meeting, San Francisco, CA, September 10 - 14, 2006.
Abstract: In the symposium, we will present the synthesis and properties of the mesoporous TIO2 films and membranes and fundamental and systematic study on the decomposition pathway of such biological toxins.

PRESENTATION American Health Home Survey: A National Study of Residential Related Hazards 09/02/2006
BRADMAN, K., R. HIGHSMITH, L. S. SHELDON, S. L. HARPER, S. J. VESPER, M. MEDINA-VERA, R. C. FORTMANN, E. A. COPPEDGE, C. W. CROGHAN, W. FRIEDMAN, E. PINZER, P. ASHLEY, D. COX, AND G. DEWALT. American Health Home Survey: A National Study of Residential Related Hazards. Presented at International Society for Exposure Analysis Conference, Paris, FRANCE, September 02 - 06, 2006.
Abstract: This poster was presented at the International Society for Exposure Analysis Conference in Paris, France, September 2-6, 2006

PRESENTATION Modeling Excess Dietary Exposure 09/02/2006
MELNYK, L. J., M. Z. BYRON, G. BROWN, A. CLAYTON, AND L. MICHAEL. Modeling Excess Dietary Exposure. Presented at International Soeciety of Exposure Analysis Annual Meeting, Paris, FRANCE, September 02 - 06, 2006.
Abstract: This abstract and poster were presented at the International Society of Exposure Analysis Meeting, Paris, France, September 2-6, 2006.

PRESENTATION Gc X Gc-Tofms of Synthetic Pyrethroids in Foods 08/21/2006
COCHRAN, J., P. KAUFFMAN, T. E. HIEBER, AND J. N. MORGAN. Gc X Gc-Tofms of Synthetic Pyrethroids in Foods. Presented at Dioxin 2006, Oslo, NORWAY, August 21 - 25, 2006.
Abstract: This abstract was presented at the Dioxin 2006 Conference in Oslo, Norway, August 21-25, 2006.

PRESENTATION Development of the EPA Relative Moldiness Index© and Its Relationship to Health 07/24/2006
VESPER, S. J. Development of the EPA Relative Moldiness Index© and Its Relationship to Health. Presented at ASTM Conference, Boulder, CT, July 24 - 26, 2006.
Abstract: This study compared two binary classification methods to evaluate the mold condition in 271 homes of infants, 144 of which later developed symptoms of respiratory illness. A method using on-site visual mold inspection was compared to another method using a quantitative index of moldiness, calculated from mold specific quantitative PCR (MSQPCR) measurements on the concentration of 36 species of molds in floor dust samples called the EPA relative moldiness index© (ERMI©).

PRESENTATION Detoxification of Cyanobacterial Toxin Contaminated Water Using Tio2 Photocatalytic Films 07/17/2006
ANTONIOU, M. G., H. CHOI, A. A. DELACRUZ, AND D. D. DIONYSIOU. Detoxification of Cyanobacterial Toxin Contaminated Water Using Tio2 Photocatalytic Films. Presented at HPLC 2006 Conference, San Francisco, CA, June 17 - 23, 2006.
Abstract: Cyanobacterial harmfal algal blooms (CyanoHABs) often produce undesirable color, odor and taste and more importantly, potent toxins that can cause chronic, acute and acute letha poisonings to wild and domestic animals and humans

PRESENTATION Gc X Gctofms of Synthetic Pyrethroids in Foods Samples 07/16/2006
COCHRAN, J., P. KAUFFMAN, T. E. HIEBER, AND J. N. MORGAN. Gc X Gctofms of Synthetic Pyrethroids in Foods Samples. Presented at Florida Pesticide Residue Workshop, Orlando, FL, July 16 - 20, 2006.
Abstract: Pyrethrins are natural insecticides in the extract of chrysanthemum flowers1. Pyrethroids are synthetic forms of pyrethrins, and many are halogenated (F, Cl, Br). Synthetic pyrethroids have become popular replacements for organophosphorus pesticides, which have become increasingly regulated due to health and environmental concerns. Synthetic pyrethroids were designed to be more stable than pyrethrins, and therefore have the potential to be found in the environment, and in food, as trace residues. They are highly toxic to aquatic organisms and some may be endocrine disruptors and/or carcinogens. Typical methods for their analysis include gas chromatography - electron capture detector (GC-ECD)2, GC - electrolytic conductivity detector (ELCD)3, and GC - mass spectrometry (MS)4.
A relatively new way to solve separation problems for complex samples, including those for food analysis, is to use comprehensive two-dimensional GC (GCxGC). GCxGC increases peak capacity by applying two independent separations to a sample in one analysis. Typically, GCxGC involves a serial column configuration (employing orthogonal phases) separated by a thermal modulator. Due to modulation, most GCxGC peaks are on the order of 50 to 250 ms wide, requiring a fast detector. When mass spectrometry is used, only time-of-flight (TOF) has the necessary acquisition rates (hundreds of spectra/sec). The ability of the thermal modulator to narrow peaks (thereby increasing their height) prior to their detection also affords the ability to increase TOFMS sensitivity, which can be important for the analysis of trace levels of pesticides in food samples, not only to increase their detection, but also to allow moderate (1 to a few microliters) sample sizes to be introduced to the GC. Keeping the sample introduction volume low, especially in food analysis, helps preserve the integrity of the chromatographic system.

GCxGC with a flame ionization detector (FID) was recently employed for the analysis of pyrethrins (cinerins, jasmolins, pyrethrins) in a chrysanthemum extract5. Since these pyrethrins are thermally labile, on-column injection and, very short primary and secondary columns were used. Fast GCxGC with a short primary column allowed the unbiased determination of the pyrethrins in the complex extract, but the technique was not used for synthetic pyrethroid analysis. The paper offered here demonstrates GCxGC-TOFMS for the analysis of synthetic pyrethroids, with an emphasis on those that contain halogens. A pyrethroid-spiked composite food extract is used to demonstrate the utility of GCxGC-TOFMS for complex matrices.


PRESENTATION Ord's Research on Pathogens in Biosolids 07/12/2006
FOUT, G. Ord's Research on Pathogens in Biosolids. Presented at Water Environmental Federal Pacific Southwest Organics Residuals Symposium, Sacramento, CA, July 12 - 14, 2006.
Abstract: In 2002 the National Academy of Sciences issued a report on EPA's regulations governing the preparation of class A and B biosolids. They stated that the science supporting the rule was outdated and recommended that EPA develop new standardized methods for measuring pathogens in biosolids. They also recommended that the Agency "promote research which uses improved pathogen detection technology to better establish the reliability of its pathogen treatment processes and biosolids-use controls to achieve and maintain minimal exposure over time." EPA responded to this report by developing and validating methods 1680 and 1681 for fecal coliform bacteria, method 1682 for the Salmonella, and by initiating the development of new methods for enteric viruses. This presentation discusses the problems associated with the original methods specified in the regulations and describes the development of the new methods.

PRESENTATION Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Based Analysis of Giardia Lamblia 06/20/2006
VILLEGAS, E., S. GLASSMEYER, M. W. WARE, S. L. HAYES, AND F. W. SCHAEFER. Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Based Analysis of Giardia Lamblia. Presented at IX International Workshop on Opportunistic Protists, Lisbon, PRINCIPLE, June 20 - 24, 2006.
Abstract: Giardia lamblia is a zoonotic protozoan parasite that is a leading cause of drinking water related gastro-intestinal disease outbreaks worldwide. Due to the genotypic complexity and high prevalence of this parasite in the environment, numerous research studies are being done to genotype the different Giardia species present in clinical and environmental samples. One approach used to genotype these pathogens is nested PCR in combination with restriction fragment length polymorphism (RFLP) analysis. However, this approach can be labor intensive, expensive, and prone to PCR contamination. In this study, we evaluated the utility of matrix assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as an alternative method to identify different Giardia species. MALDI-TOF MS analyses of G. lamblia and G. muris reveal mass spectral fingerprints that contain genus and species specific peaks. Further analysis of flow cytometry sorted G. lamblia trophozoites identified trophozoite specific peaks that constituted a part of the total mass spectral fingerprint detected from live G. lamblia cysts. In addition, to determine the stability of these G. lamblia mass spectral profiles, live cysts and cysts killed by physical and/or chemical disinfection were also analyzed by MALDI-TOF MS. Results reveal the loss of specific peaks in killed cysts as compared to live cysts. These results suggest that a MALDI-TOF MS based proteomics approach is effective at identifying unique mass spectral fingerprints from two different Giardia species and differentiating viable from non-viable cysts. This study presents an alternative approach for identifying various clinical and/or environmental Giardia isolates as well as a method to evaluate various drinking water treatment and disinfection efficacies.

PRESENTATION USEPA's Approach to the Development of New Analytical Methods for Emerging Contaminants in Drinking Water 06/07/2006
MUNCH, J. W. AND J. A. SHOEMAKER. USEPA's Approach to the Development of New Analytical Methods for Emerging Contaminants in Drinking Water. Presented at Groundwater Resources Association of California 18th Symposium on Groundwater Contaminants "Emerging Contaminants in Groundwater: A Continually Moving Target, Concord, CA, June 07 - 08, 2006.
Abstract: The 1996 Amendments to the Safe Drinking Water Act require USEPA to perform Unregulated Contaminant Monitoring (UCM) for chemicals of interest to the Agency for possible future regulation. Many of these chemicals fall into the category of "emerging contaminants". An important element of UCM is the use of sensitive and specific analytical methods for nationwide monitoring of finished drinking water. As part of the regulatory determination process, the Agency uses this data to assess exposure to these contaminants by drinking water consumers. The Office of Research and Development's National Exposure Research Laboratory is one of the two primary sources within USEPA for the development of analytical methods used for UCM and for the analysis of emerging contaminants in drinking water.

Brief descriptions of the research associated with recently completed methods for acetanilide degradation products and nitrosamines (including NDMA) will be presented. Current ORD research activities, which include the development of a solid phase extraction (SPE) LC/MS/MS method for the analysis of perfluorinated compounds, and an SPE GC/MS method for water soluble volatile compounds including t-butyl alcohol and 1,4-dioxane, will also be presented.

PRESENTATION Development of Biomarker of Exposure to Viral Pathogens 06/01/2006
LI, L. AND A. P. DUFOUR. Development of Biomarker of Exposure to Viral Pathogens. Presented at FOCIS, San Francisco, CA, June 01 - 05, 2006.
Abstract: Interferon gamma (IFN-γ) was selected as a biomarker for a viral exposure study. Twelve-week-old BALB/c mice were intraperitoneally injected with 0.2ml of 104 PFU/ml of coxsackievirus B3 or B4 diluted in phosphate-buffered saline (PBS). Control mice were injected with PBS only. Four months after viral infection mouse thymus and spleen were collected. T lymphocytes were isolated from the organs and assayed for proliferation to release IFN-γ under ex vivo stimulation (incubation) with viral antigens, a mitogen PHA and PBS respectively. The level of IFN-γ released by T lymphocytes was examined by antibody-capture chemiluminescent ELISA. A marked increase in the level of IFN-γ was observed when T cells from coxsackievirus B3 infected mice were incubated with B3 virus but not B4 and PBS. This indicated that coxsackievirus B3- sensitized T cell receptors recognized only T cell epitopes from B3 virus not B4. By the same token, primed T cells from mice infected by coxsackievirus B4 were not stimulated to produce IFN-γ when they were incubated with B3 virus and PBS. T cells from mice injected with PBS did not release IFN-γ because they did not recognize both B3 and B4 viruses. These T cells did release IFN-γ under stimulation of PHA. Our results demonstrated that IFN-γ produced by memory (sensitized or primed) T cells is virus-specific and can be used as a biomarker in viral infection studies. The data also demonstrated that the memory T cell receptor can distinguish different T cell epitopes from highly structurally related coxsackievirus B3 and B4 when the sensitized T cells were directly stimulated by the viruses ex vivo. The results of this study may be extended to human exposure studies related to microbial pathogens.

PRESENTATION Footprints in the Sand: Where We Have Come from and Where We Need to Go in Recreational Water Research 05/25/2006
DUFOUR, A. P. Footprints in the Sand: Where We Have Come from and Where We Need to Go in Recreational Water Research. Presented at American Society for Microbiology Annual Meeting, Orlando, GA, May 25, 2006.
Abstract: New rapid methods will be discussed, including their advantages and disadvantages. This presentation will also provide a historical perspective on the evolution of water quality standards and the rationale for risk-based regulations for recreational waters.

PRESENTATION An Integrated Cell Culture/Rt-Pcr Method for Detecting Enterovirus in Water 05/21/2006
VILLEGAS, L. F. AND G. FOUT. An Integrated Cell Culture/Rt-Pcr Method for Detecting Enterovirus in Water. Presented at American Society for Microbiology 106th General Meeting, Orlando, FL, May 21 - 25, 2006.
Abstract: Echovirus and coxsackievirus can cause mild to severe disease following consumption of contaminated drinking water. However, comprehensive occurrence studies of enteroviruses in drinking water matrices are limited, in part because of the lack of available methods that are rapid, sensitive, and able to detect infectious virus. To address this issue, the US EPA has included echoviruses and coxsackieviruses on the microbial contaminant candidate list (CCL). To provide the research needed to support regulatory decisions for these CCL viruses, our efforts have focused on developing methods for the rapid detection of infectious virus. It has become increasingly important to design a method which can detect infectious virus in a rapid and sensitive matter. To achieve this goal, we have developed a technique which integrates cell culture and molecular assays into one method. This integrated cell culture/reverse transcription polymerase chain reaction method (ICC/RT-PCR) approach uses molecular tools to rapidly detect infectious enterovirus in water matrices.

PRESENTATION Influence of Fat and Moisture Content on Foods on Transfer of Pesticides 05/21/2006
MELNYK, L. J., T. E. HIEBER, AND C. E. BERNARD. Influence of Fat and Moisture Content on Foods on Transfer of Pesticides. Presented at European Pesticide Residue Workshop , Corfu, GREECE, May 21 - 25, 2006.
Abstract: Tranfer efficiencies (%) of eight pesticides from a Formica surface to 13 different foods were measured to estimate dietary exposure potential from contacts prior to consumption. the foods were categorized into four groups: 1) high fat, high moisture; 2) low fat, high moisture; 3) high fat, low moisutre; and 4) low fat, low moisture to determine if these characterizations affected transfer. Fat content was calculated from nutritional information on the packaging. A moisture analyzer was used to thermogravimetrically measure water content of each food item. Surface loading was determined by wiping with isopropanol-moistened gauze pads.
The average transfer efficiencies were 75.1, 75.9, 4.7 and 7.3% for categories 1, 2, 3 and 4,respectively (see above). Analysis of variance and a Tukey multiple comparison test were used to assess mean transfer efficiencies among the eight pesticides and identify significant differences between food groups. Significant differences in transfer efficiency among the food groupings only correlated to moisture content of the food.

PRESENTATION Comparison of Real-Time Pcr Fecal Bacteria Measurements in Recreational Waters Using Different Instruments and Reagent Systems 05/21/2006
HAUGLAND, R. A., S. SIEFRING, M. VARMA, E. ATIKOVIC, AND L. J. WYMER. Comparison of Real-Time Pcr Fecal Bacteria Measurements in Recreational Waters Using Different Instruments and Reagent Systems. Presented at 106th General Meeting of the American Society for Microbiology, Orlando, FL, May 21 - 25, 2006.
Abstract: U.S. EPA guidance on the safety of surface waters for recreational use is currently based on concentrations of culturable fecal indicator bacteria. Attention is now shifting to more rapid molecular monitoring methods. A multi-year epidemiological study is in progress to determine the relationship between illness rates in bathers and concentrations of fecal bacteria in recreational water as determined by real-time PCR analysis. Analyses in the first 2 years of the study were limited to one PCR reagent and type of instrument. Acceptance of this technology will be aided by the availability of choices in instruments and newer PCR reagents that offer even shorter analysis times. DNA extracts of 50 ml beach water filtrates (N = 396) collected from Biloxi, MS during the 2005 study were analyzed on 3 instruments: Applied Biosystems model 7700 (analysis time ~ 2 hr); Cepheid Smart Cycler (analysis time ~ 30 min with TaqMan probe & ~45 min with Scorpion probe); and Applied Biosystems fast block model 7900 (analysis time ~ 35 min), using customized PCR reagents and primer/probe sets for each instrument. Mean Enterococcus and Bacteroidetes calibrator cell equivalents/filtrate determined from all analyses were 37 and 388 (CV between instrument means: 0.26 and 0.24), based on an amplification efficiency of 0.92 for both assays. Significant differences (P < 0.05) were found in the means for both groups of organisms between each of the systems with exception of the Bacteroidetes results on the models 7700 and 7900. Normalization of results using reference control analyses made these differences non-significant in all comparisons except those involving the model 7700. Failure to show comparability between model 7700 and other systems results may be related to the use of a different reference assay. Variance in replicate analyses was highest on the model 7700; this system gave a significantly lower percentage of non-detects. Our results suggest that different instrument/reagent systems can give comparable results but further analyses are needed to demonstrate relationships between epidemiological results and fecal bacteria measurements with the newer systems.

PRESENTATION Evaluation of a Generic Array Approach for Genotyping Noroviruses 05/21/2006
BRINKMAN, N. AND G. FOUT. Evaluation of a Generic Array Approach for Genotyping Noroviruses. Presented at 106th General Meeting of the American Society of Microbiology, Orlando, FL, May 21 - 25, 2006.
Abstract: Noroviruses are the leading cause of nonbacterial gastroenteritis outbreaks in the United States. Because of their potential to contaminate drinking water, the U.S Environmental Protection Agency has included noroviruses on the Contaminant Candidate List (CCL) to assess the public health risk posed by this group of viruses through waterborne routes. Typically, detection and genotype identification of these viruses rely on reverse transcriptase-polymerase chain reaction (RT-PCR) followed by probe hybridization or sequencing of the products. Although sequencing would provide the best way to genotype a sequence, probe hybridization offers the potential for a more rapid and higher throughput analysis of nucleic acids. However, due to the vast genetic diversity of noroviruses, probe hybridization would necessitate the use of multiple probes per genotype. Towards this end, we evaluated the use of a generic array format to examine the feasibility of genotyping noroviruses by probe hybridization. A genomic region of the pol gene is amplified by RT-PCR, and amplicons are used in a single base extension (SBE) reaction where genotype-specific probes are 3-biotinylated. The probes are then hybridized to an Affymetrix GenFlex Tag Array and the resulting fluorescent intensities are calculated. To examine the ability of the SBE-generic array approach to genotype Genogroup I and II norovirus stains, probes that match perfectly, as well as those that contain mismatches of varying number and position were designed. Our results show that, for all strains examined, the perfect-matched tag-probes are labeled in SBE reactions while the mismatched tag-probes are not labeled. Furthermore, in reactions with multiple norovirus templates, only the appropriate perfect-match tag-probes are labeled. These proof-of-concept results demonstrate the utility of this approach when used in combination with additional sequences conducive to genotyping. Moreover, this SBE-generic array format can be adapted to include the simultaneous identification of multiple waterborne pathogens.

PRESENTATION Determination of Pyrethroid Pesticides in Composite Dietary Samples 05/21/2006
MORGAN, J. N., P. KAUFFMAN, T. E. HIEBER, AND J. BRISBIN. Determination of Pyrethroid Pesticides in Composite Dietary Samples. Presented at European Pesticide Residue Workshop, Corfu, GREECE, May 21 - 25, 2006.
Abstract: The U.S. Environmental Protection Agency's National Exposure Research Laboratory (NERL) conducts aggregate exposure studies for determining an individual's exposure to a broad range of target analytes in composite dietary samples. The objective of this work is to develop an analytical method, with sub-part per billion (ppb) detection limits, for the determination of pyrethroid pesticides in composite dietary samples collected in exposure studies.
Pressurized solvent extraction (hexane, acetonitrile, and hexane/acetone) and clean-up with solid phase sorbents (diatomaceous earth, alumina, graphitized carbon black and primary secondary amine) were evaluated for both lyophilized and wet composite food samples. Detection techniques included gas chromatography/mass spectrometry in the selected ion monitoring mode and gas chromatography/tandem mass spectrometry. Target performance criteria were 60-140% recovery, 30% relative standard deviation, and sub-ppb detection limits. Results suggest that recoveries in this range are generally achievable, while sub-ppb detection limits may present a significant challenge. A comparison of method performance parameters, including recovery, precision and detection limits, using a variety of extraction parameters, clean-up procedures, and detection techniques, will be presented.

PRESENTATION Development of a Biomarker System for Detecting Exposure to Waterborne Viral Pathogens 05/16/2006
LI, L. AND A. P. DUFOUR. Development of a Biomarker System for Detecting Exposure to Waterborne Viral Pathogens. Presented at 2006 EPA Science Forum, Washington, DE, May 16 - 18, 2006.
Abstract: EPA has published a drinking water contaminant candidate list (CCL) that includes waterborne pathogens and chemicals that may be considered for regulation at a future date. For each contaminant on the CCL, the Agency will need sufficient data to conduct analyses on the extent of exposure and the risk posed to populations via drinking water. Previous studies indicated that exposure to some microbes, including the CCL pathogen coxsackievirus B3 and B4, may be associated with serious long-term health consequences (sequela), such as myocarditis and type-1 diabetes. However, little is known about waterborne-associated infections by these microbes and their linkage to chronic diseases. This presentation discusses the development of a biomarker system for detecting expsoure to waterborne viral pathogens.

PRESENTATION Monitoring Fecal Indicator Bacteria With Alternative Real-Time Pcr Instruments to Assess Health Risks Associated With Recreational Water Use 05/16/2006
VARMA, M., S. SIEFRING, E. ATIKOVIC, L. J. WYMER, AND R. A. HAUGHLAND. Monitoring Fecal Indicator Bacteria With Alternative Real-Time Pcr Instruments to Assess Health Risks Associated With Recreational Water Use. Presented at 2006 EPA Science Forum, Washington, DC, May 16 - 18, 2006.
Abstract: U.S. EPA guidance on the safety of surface waters for recreational use is currently based on epidemiological studies conducted in the 1980?s that demonstrated a strong positive correlation between bathing-associated illness rates and concentrations of culturable fecal indicator bacteria in these waters. Culture-based methods for quantifying fecal indicator bacteria require at least 24 hours for results. Because swimmers may be exposed to unsafe waters during this time, attention is now shifting to molecular monitoring methods that generate results in the same day. A multi-year epidemiological study is in progress to determine the relationship between illness rates and concentrations of fecal bacteria in recreational waters as determined by real-time PCR analysis. Analyses in the first 2 years of the study (2003-2004) were limited to one PCR reagent and type of instrument. Acceptance of this technology will be aided by the availability of choices in instruments and newer PCR reagents that offer even shorter analysis times. Studies were conducted to compare the performance of three instruments and associated reagent systems: Applied Biosystems model 7700 (analysis time ~ 2 hr); Cepheid Smart Cycler (analysis time ~ 30 min with TaqMan probe & ~45 min with Scorpion probe); and Applied Biosystems fast block model 7900 (analysis time ~ 35 min), for the detection of two fecal bacteria groups, Enterococcus and Bacteroidetes, in surface waters. PCR probe and primer sets originally developed for detection of these organisms on the model 7700 gave less sensitive and precise measurements on the faster Smart Cycler and model 7900 instruments. Modifications of the PCR probe and primer sets improved the performance on these instruments. DNA extracts of 50 ml beach water filtrates (N = 396) collected from Biloxi, MS during the 2005 epidemiological study were analyzed on the three instruments using optimal probe and primer sets for each instrument. Mean Enterococcus and Bacteroidetes calibrator cell equivalents/filtrate determined from all analyses were 37 and 388 (coefficient of variation among instrument means: 0.26 and 0.24 respectively). Significant differences (P < 0.05) were found in the means for both groups of organisms between each of the systems with the exception of the Bacteroidetes results on the models 7700 and 7900. Normalization of results using reference control analyses made these differences non-significant in all comparisons except those involving the model 7700. Failure to show comparability between model 7700 and other systems results may be related to the use of the different probe and primer sets. Analyses will be performed to determine the relationships between bathing-associated illness rates and measurements of both Enterococcus and Bacteroidetes on each of the three instruments. Results of these analyses will determine whether results from different real-time PCR instruments show the same positive correlation with illness rates that has been established thus far in the EPA epidemiological study. They will also provide additional data for the Office of Water to use in formulating new health risk-based water quality guidelines associated with this technology.

PRESENTATION Susceptibility to Asthma Controlled By Modifying the Environment 05/16/2006
VESPER, S. J. Susceptibility to Asthma Controlled By Modifying the Environment. Presented at 2006 EPA Science Forum, Washington, DC, May 16 - 18, 2006.
Abstract: In a just completed five year study in Cleveland area water-damaged homes of asthmatics, EPA ORD researchers, in collaboration with Case Western Reserve University Medical School, established that specific molds were statistically more common in water-damaged homes. When the molds were removed from these homes, the children had a significant decrease in asthma symptoms and symptom days. The result was a statistically significant 10-fold reduction in the use of medical interventions, i.e. either emergency room visits or hospital admissions, for children living in these homes.
In a just completed study in Cincinnati, the relationship between mold concentrations and the development of wheeze and/ or rhinitis in infants was tested. To measure exposure risk, EPA scientists developed the EPA relative moldiness index) or ERMI) based on the measurement of the concentration of 36 species of molds in floor dust samples by using EPA's patented "Mold Technology". The ERMI) values were used to accurately predict the risk for infants developing respiratory illness.

By applying these finds and techniques, we should be able to reduce the asthma burden in the US, reduce the use of medical care and save lives.

PRESENTATION Rapid Health-Based Method for Measuring Microbial Indicators of Recreational Water Quality 2006 EPA Science Forum 05/16/2006
BRENNER, K. P., R. L. CALDERON, A. P. DUFOUR, R. A. HAUGLAND, E. A. SAMS, T. J. WADE, AND S. SIEFRING. Rapid Health-Based Method for Measuring Microbial Indicators of Recreational Water Quality 2006 EPA Science Forum. Presented at 2006 EPA Science Forum, Washington, DC, May 16 - 18, 2006.
Abstract: Because the current approved cultural methods for monitoring indicator bacteria in recreational water require 24 hours to produce results, the public may be exposed to potentially contaminated water before the water has been identified as hazardous. This project was initiated to evaluate rapid health-based methods that could obtain results the same day the water was collected. During the summers of 2003 and 2004, a freshwater recreational water quality study, using the rapid (results in < 2 hours) Quantitative Polymerase Chain Reaction (QPCR) method for Enterococcus detection, and a swimmer health study were conducted concurrently at four freshwater Great Lakes beaches. Water samples were collected using a modification of the new EPA water sampling protocol. Swimmers were interviewed on the beach and telephoned 10-12 days later to determine their health status following the swimming event. The results of the study showed that the Enterococcus concentrations, obtained using the QPCR method, were significantly correlated with swimming-associated gastroenteritis. The data from this research study will be used by the EPA Office of Water to develop new health-based criteria and guidelines for recreational water quality based on "real time" monitoring. The rapid QPCR method, which produces results within 2 hours of sample collection, will allow beach managers and public health officials to alert the public about potential health hazards in a timely manner, thereby reducing illness from recreational water use.

PRESENTATION An Improved Method for Detecting Viruses in Water 05/15/2006
VILLEGAS, L. F. An Improved Method for Detecting Viruses in Water. Presented at 2006 EPA Science Forum, Washington, DC, May 15 - 18, 2006.
Abstract: Enteroviruses are important etiological agents of waterborne disease and are responsible for outbreaks of gastroenteritis. However, the prevalence and occurrence of these pathogens in raw drinking water sources is poorly understood. This is primarily due to the limited methods available to detect enterovirus in water. Current detection methods often rely on two techniques; cell culture assays, which require long growth periods, or molecular assays, which do not provide information about viability. Combining these two techniques could result in the rapid detection of viable virus. Several integrated cell culture/RT-PCR techniques have been developed, however the method described here has several unique improvements. This approach involved filtering 200 liters of surface water through a 1MDS cartridge filter and eluting twice using 1.6 liters of 1.5% beef extract. The elutions were concentrated using celite, and furter concentrated by ultracentrifugation. The concentrated samples were then innoculated into two culture tubes of BGM cell monolayers, and allowed to grow for 1-7 days post-infection. Aliquots of the cell lysate were taken at different time points, and tested by qRT-PCR or RT-PCR while the remaining cell culture supernatant was used to innoculate a new monolayer, allowiong for further virus replication. Using this new method, 10 PFU of poliovirus can be detected by qRT-PCR within 24 hours while as little as 1PFU can be detected after 2 days of growth in the culture. Similarly, environmental samples spiked with 30 PFU can be detected in 24 hours by qRT-PCR. The ICC/RT-PCR method presented here provides a faster and more sensitive approach to detecting viable virus from environmental samples as compared to previous detection methods. Moreover, this method greatly minimized the loss of virus in samples by using a serial passage technique during the cell culture phase of the method, and the use of qRT-PCR greatly reduces the risk of molecular contamination.

PRESENTATION Recreational Beach Water Quality Monitoring With Quantitative Polymerase Chain 05/01/2006
HAUGLAND, R. A. Recreational Beach Water Quality Monitoring With Quantitative Polymerase Chain. Presented at Region 2 LTIG Conference, Newark, NJ, May 01 - 04, 2006.
Abstract: Recreational beaches are an important economic and aesthetic asset to communities, states and the nation as a whole. Considerable resources are expended each year in monitoring the water at these beaches for fecal indicator bacteria as a means of determining if it is safe for public use. Indicator bacteria measurements are presently performed by culture-based methods such as membrane filtration that require at least 24-hour before results are obtained. As a result, these methods often may not allow notification of potential health risks to swimmers until after exposures have occurred. Several molecular microbial analysis technologies have the capability of circumventing this deficiency by providing results in shorter time periods. One particularly rapid technology is the quantitative polymerase chain reaction (QPCR). Water analyses using this technology can provide results in approximately 2-4 hours. This technology has now been adapted for the measurement of the EPA-recommended fecal indicator organisms Eschericia coli and Enterococcus, as well as a promising new group of fecal indicator bacteria in the class Bacteroidetes, in surface water samples. In 2003-2004 studies were conducted by the U.S. EPA, Office of Research and Development (ORD), to determine the correlation between QPCR and EPA Method 1600 (membrane filtration) measurements of enterococci in water samples and swimmer illness rates at four Great Lakes beaches. Positive correlations were observed between the results of these two analytical methods and between the results of the QPCR method and swimmer illness rates. In 2005 a similar study was initiated for a marine beach on the Gulf of Mexico. This presentation will provide an overview of the ORD national beaches study, describe the QPCR method and its application for beach water quality analysis and discuss recent work on the optimization of assays and controls for use with different commercially available instrument and reagent systems.

PRESENTATION Re-Use of Electropositive Cartridge Filters for Concentrating Viruses from Water 04/04/2006
CASHDOLLAR, J. Re-Use of Electropositive Cartridge Filters for Concentrating Viruses from Water. Presented at USEPA Large Volume Sample Preparation for Waterborne Pathogens Workshop, Cincinnati, OH, April 04, 2006.
Abstract: This presentation describes a project that evaluated the efficacy of reusing positively charged filters to collect waterborne viruses.

PRESENTATION Methods and Microbes for Measuring the Quality of Recreational Waters: Past, Present and Future 03/31/2006
DUFOUR, A. P. Methods and Microbes for Measuring the Quality of Recreational Waters: Past, Present and Future. Presented at Florida Branch of the American Society for Microbiology, Cocoa Beach, FL, March 31 - April 01, 2006.
Abstract: The methods and microbes used to measure the quality of recreational waters have changed very little over the last sixty years. The use of microbial indicators used to measure the quality of water under various conditions across the United States, and the serious shortcomings that frequently preclude their use will be discussed, as well as possible solutions to problem issues.

PRESENTATION Characterization of Sulfur Containing Analogs of Monomethylarsonic Acid in Aqueous Phase Standards and Carrot Extracts By Ic-ICP-MS and Ic-Esi-MS/MS 03/26/2006
FRICKE, M., P. A. CREED, C. A. SCHWEGEL, JOHN T. CREED, S. K. YATHAVAKILLA, AND S. CONKLIN. Characterization of Sulfur Containing Analogs of Monomethylarsonic Acid in Aqueous Phase Standards and Carrot Extracts By Ic-ICP-MS and Ic-Esi-MS/MS. Presented at American Chemical Society Ar Symposium, Atlanta, GA, March 26 - 31, 2006.
Abstract: Recently, sulfur analogs of well known arsenicals have been identified, generating a need for stable species-specific standards. This presentation will focus on the identification and characterization of a novel species, monomethylthioarsonic acid (MMTA), in carrots. A standard of MMTA was synthesized by reacting monomethylarsonic acid (MMA) with H2S. High-resolution ESI-MS/MS indicates that MMTA is produced. While MMTA appears to be stable in solution, attempts at crystallization have resulted in degradation of MMTA to MMA. USing IC-ICP-MS, MMTA was identified in carrot samples as indicated by chromatographic co-elution with the synthesized standard. However, confirmation by IC-ESI-MS/MS has been hampered by sensitivity issues. The origin of MMTA in carrots will be discussed considering the likely sulfur-oxygen exchange with MMA in sulfidic, reducing environments and/or previous use of methylarsine sulfide (CH3AsS)x as a fungicide.

PRESENTATION Rainwater Catchment Systems in Ohio and Kentucky 03/21/2006
LYE, D. J. Rainwater Catchment Systems in Ohio and Kentucky. Presented at Ohio Department of Health Midwest Workshop, Columbus, OH, March 21, 2006.
Abstract: There is no abstract for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Biomarkers of Viral Exposure 03/17/2006
FOUT, G. Biomarkers of Viral Exposure. Presented at Biosolids Exposure Workshop, Cincinnati, OH, March 17, 2006.
Abstract: Viral and protozoan pathogens associated with raw sludge can cause encephalitis, gastroenteritis, hepatitis, myocarditis, and a number of other diseases. Raw sludge that has been treated to reduce these pathogens can be used for land application according to the regulations specified in 40 CFR Part 503. However, little data on the efficacy of typical full-scale treatment processes employed to inactivate pathogens found in biosolids exists due to the high cost of assays. In addition, while laboratory-scale studies are often used to demonstrate the effectiveness of new treatment processes, the methods available do not detect all of the pathogens that would be expected to cause disease following biosolids applications.
EPA has received numerous complaints from individuals and environmental groups stating that people and livestock near biosolids applications have experienced illness. However, outbreaks have not been linked to biosolids applications. Nevertheless, more research is needed to verify that there is no risk associated with this practice. Epidemiological-based studies that could provide needed exposure data are expensive, difficult to conduct and interpret and, more importantly, usually exclude children, who are more susceptible than adults to many of the diseases that are associated with enteric pathogens. As suggested by the National Research Council in 2002, better methods for exposure measurement are needed.

EPA has initiated a new study of infections from drinking water using technology that is directly applicable to biosolids exposure studies. The new study will target salivary antibodies to assess exposure to Cryptosporidium, noroviruses and rotaviruses. Saliva has major advantages over serum as a medium for antibody detection in that the non-invasive collection of saliva can be applied to children and is much more acceptable to all study participants. The study is using a novel, highly sensitive analytical method for antibody analyses. The method uses an array of fluorescent beads, which allows simultaneous detection and quantification of salivary antibody responses to multiple pathogens and immunoglobulin types in a single assay. This system has significantly less cost and variability than standard enzyme-linked immunosorbent assays. The drinking water exposure study will measure immune responses in study participants on a monthly basis before and after a new drinking water treatment plant that meets bin 2, Long Term 2 Enhanced Surface Water Treatment Rule requirements comes on line. This presentation will discuss the methods used in the drinking water study and how they would be applicable to similar studies related to biosolids.

PRESENTATION Dimethylithioarsinic Anhydride: A Standard for Arsenic Speciation 03/12/2006
FRICKE, M., M. ZELLER, S. CONKLIN, P. A. CREED, C. A. SCHWEGEL, M. WITKOWSKI, AND JOHN T. CREED. Dimethylithioarsinic Anhydride: A Standard for Arsenic Speciation. Presented at Pittsburg Conference, Orlando, FL, March 12 - 16, 2006.
Abstract: Recently, sulfar analogs of well know arsenicals have been identfied in biolgical, dietary and environmental matrices. These discoveries have generated a need for stable species-specific standards. This presentation will forcus on the isolation and characterization of a standard for dimethylthioarsinic acid. Dimethylthioarsinic acid (DMTA) is a naturally occurring arsenical that has recently been identified as a potential arsenic arcinogen. To date, determination of this species has been by chromatographic retention time to match to analytical standards generated in vitro by the reaction of dimethylarsinic acid (DMA) with hydrogen sulfide (H2S). The reaction generates multiple arsenic-containing products which has hampered the isolation of the initially formed species, DMTA. This was overcome by chromatographic monitoring of the formation of the products from DMA + H2S. The reaction was iteratively advanced until 90% of the DMA starting material was converted to DMTA. No other products were observed at this point in the reaction progress. Isolation of DMTA was by organic techniques and facialitated by the solubility of the product in nonpolar media as compared to the starting material. Single crystal diffraction demonstrated that DMTA as a solid had been isolated as the oxygen-bridged dimethylthioarsinic anhydride. The anhydride form of DMTA was determined as a suitable standard because of the ease of isolation, the long term stability of the crystalline standard, and the rapid conversion of the anhydride to the acid upon dissolution in water.

PRESENTATION Progress in Standardization and Validating the 503 Approved Microbiological Methods of Analysis Enteric Viruses 03/12/2006
FOUT, G. Progress in Standardization and Validating the 503 Approved Microbiological Methods of Analysis Enteric Viruses. Presented at WEF Residuals and Biosolids Management Conference, Covington, KY, March 12, 2006.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Fate of Pharmaceuticals: Effects of Chlorination and Environmental Persistence 03/12/2006
GLASSMEYER, S., E. L. FURLONG, D. L. KOLPIN, J. D. CAHILL, S. D. ZAUGG, S. L. WERNER, M. T. MEYER, AND D. D. KRYAK. Fate of Pharmaceuticals: Effects of Chlorination and Environmental Persistence. Presented at 57th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, Orlando, FL, March 12 - 17, 2006.
Abstract: The presence of pharmaceuticals in environmental waters has become an area of concern around the world. To maximize the impact of occurrence studies, pre-screening can help determine which compounds are likely to survive waste water treatment, as well as what by-products are formed. To investigate the effects of chlorination on pharmaceuticals, a group of fourteen pharmaceuticals and common human pharmaceutical metabolites were analyzed using liquid chromatography/mass spectrometry. Six of the target compounds were unaffected by chlorination and eight were transformed due to chlorination. Only two of the pharmaceuticals - acetaminophen, gemfibrozil - were found to become chlorinated during the experiments. These simple screening tests can help determine which pharmaceuticals or their by-products should be targeted in future occurrence studies. To further examine the fate of pharmaceuticals in the environment, they and other chemicals found in human wastewater, were evaluated as tracers of human fecal pollution. At ten locations, water samples were collected upstream, and at two points downstream from a wastewater treatment plant. A treated effluent sample was also collected at each location. Seventeen of the 110 compounds were classified as either a prescription or non-prescription pharmaceutical. Of these, nine were found in at least 50% of the samples and thirteen were found in at least 10% of the samples. The concentrations of the majority of the chemical compounds present in the samples generally followed an expected trend: 1) they were non-existent or at only trace levels in the upstream samples, 2) had their maximum values in the wastewater effluent samples, and 3) declined in the two downstream samples. This work indicates that these chemical analytes do have utility as tracers of human wastewater discharge.

PRESENTATION Initial Characterization of Monoclonal Antibodies Against the Fungal Hemolysin Stachylysin from Stachybotrys Chartarum 03/03/2006
SCHMECHEL, D., B. J. GREEN, F. M. BLACHERE, S. J. VESPER, AND D. BEEZHOLD. Initial Characterization of Monoclonal Antibodies Against the Fungal Hemolysin Stachylysin from Stachybotrys Chartarum. Presented at Annual Meeting of the American Academy of Allergy, Asthma and Immunology, Miami, FL, March 03 - 06, 2006.
Abstract: Stachybotrys chartarum is known to produce the hemolysin stachylysin and its detection in human serum has been proposed as a biomarker for exposure to the fungus. In this study we report the initial characterization of monoclonal antibodies (mAbs) against stachylysin and the development of a sandwich enzyme-linked immunosorbent assay (ELISA) for its detection.

PRESENTATION Developing a Method for Detecting Viruses in Water 02/15/2006
VILLEGAS, L. F. Developing a Method for Detecting Viruses in Water. Presented at Greater Cincinnati Water Works, Cincinnati, OH, February 15, 2006.
Abstract: There is no abstract for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Pathogen Equivalency Committee (Mceard) 01/25/2006
SMITH, J. E., B. ACQUISTO, M. C. MECKES, D. S. BROWN, G. FOUT, R. BASTIAN, S. SCHAUB, AND F. W. SCHAEFER. Pathogen Equivalency Committee (Mceard). Presented at WSWRD/NRMRL BOSC Review, Cincinnati, OH, January 25 - 27, 2006.
Abstract: Science Questions:
MYP Science Question: What is the current state of management practices for biosolids production and application, and how can those be made more effective?

Research Questions: Are there innovative or alternative sludge disinfection processes that are capable of significantly reducing pathogens (Class B, Alternative 3) or further reducing pathogens (Class A, Alternative 6) and thus meeting the requirements of 40CFR503?

What must the developer of a new/emerging sludge disinfection process do to demonstrate the capability of his/her process? In other words, what pathogens or indicator organisms must it be capable of reducing?

Is the PEC using the best criteria to evaluate unproven technologies; are the best standardized and validated analytical methods being used for quantifying fecal coliform, Salmonella spp., enteric viruses, and Ascaris spp; and are pathogens emerging that Class B or A processes may not be able to disinfect

The Research

The U.S. Environmental Protection Agency created the PEC in 1985 to make recommendations to EPA and State managers on the equivalency of unproven sewage sludge disinfection technologies/processes to either a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further Reduce Pathogens (PFRP) under the 40CFR-Part 257 and later 40CFR-Part 503 Regulations. The PEC consists of eleven members with expertise in bacteriology, virology, parasitology, wastewater engineering, medical and veterinarian sciences, statistics, and sludge regulations. It includes representatives from EPA's research and development, regional and water offices, and the Centers for Disease Control. Its members also provide guidance to applicants with new technologies on the data necessary to determine equivalency, and to permitting authorities and members of the regulated community on issues related to meeting the pathogen and vector attraction reduction requirements of Part 503. Since 1989 the PEC has authored, made available and updated every three to four years the so called White House Document (Environmental Regulations and Technology: Control of Pathogens and Vector Attraction in Sewage Sludge). It is a primary reference for regional, state and local regulatory authorities and their constituents. In addition to providing information on Class A and B processes and vector attraction reduction options, it clarifies many sampling, monitoring and analytical issues. Detail is given on applying for PSRP or PFRP equivalency.

Through deliberations on PSRP and PFRP applications, helping to put in place Quality Assurance Project Plans (QAPPs) for demonstrating equivalencies, overseeing demonstrations, and holding workshops with invited international experts, the PEC maintains an awareness of emerging pathogen, analytical method, disinfection, and risk analysis issues. In addition it is always looking for ways to improve its process evaluation criteria. A report, Contemporary Perspectives on Infectious Disease Agents in Sewage Sludge and Manure, was recently prepared and made available by the PEC. It addresses such issues as temperature tolerances of emerging or re-emerging pathogens, and appropriate indicators of effective pathogen treatment. Within the year the PEC met with a group of international experts on disinfection approaches for sewage sludge. They suggested the PEC consider how many stressors are involved when evaluating new technologies; thinking in terms of the benefit of multiple barriers. Secondly, the PEC needs to consider the effect of a proposed disinfection method on parasites, viruses, and bacteria.

The PEC is in the process of establishing a website to help applicants in submitting an application for a process proposed to be equivalent to a PFRP or PSRP. Since its creation the PEC has evaluated numerous sludge disinfection technologies/processes and recommended 13 for equivalency. New ideas for novel processes are brought to the PEC's attention at a steady pace of approximately 20-30 per year, although equivalency is not sought in all cases. An equivalency application is followed through successfully to a final recommendation at an average of one per year. Examples of equivalencies recently recommended by the PEC include an anaerobic digestion system that is unique in that it combines a thermophilic digester with a mesophilic digester for a two-phase system; a flow-through thermophilic treatment process which is significant because it is the first approved process to use continuously fed, mixed digester; and a process which achieves disinfection from contact with ammonia and elevated pressure and temperature in a plug-flow reactor. There are currently six innovative processes actively seeking equivalency including processes such as vermicomposting, and an acid-oxidative process using chlorine dioxide.

Impact and Outcomes

The PEC directly assists federal, state, and local regulatory officials by overseeing the testing of new biological, physical and chemical technologies for reducing pathogens. It thus gives utilities more alternatives for disinfecting sludges and helps to assure the public that the new processes are effective. The PEC?s equivalency recommendation process is an outlet for potentially more cost-effective sewage sludge treatment processes to become accepted under the current 40CFR503 regulations while still ensuring that any potential human health risk minimized.

PRESENTATION Arsenic Speciation in Carrot Extracts With An Emphasis on the Detection of Mma(iii) and Mmta 01/08/2006
YATHAVAKILIA, S. K., M. FRICKE, P. A. CREED, C. A. SCHWEGEL, AND JOHN T. CREED. Arsenic Speciation in Carrot Extracts With An Emphasis on the Detection of Mma(iii) and Mmta. Presented at 2006 Winter Conference on Plasma Spectrochemistry, Tucson, AZ, January 08 - 14, 2006.
Abstract: The two predominant routes of arsenic exposure are dietary ingestion and drinking water consumption. Dietary arsenic, unlike drinking water arsenic, contains a variety of arsenicals with dramatically different toxicities. The list of arsenicals detected in dietary samples continues to grow with recent emphasis on sulfur-containing analogs of arsenic oxides and the ability to differentiate between the oxidation states of methylated arsenicals. This can be partially explained by the mechanistic research, which has begun to indicate that sulfur analogs of dimethylarsinate {DMA} [1], as well as the species methylarsonite {MMA(III)} and dimethylarsinite {DMA(III)} [2], profoundly influence the observed toxicity. The scientific consensus that inorganic arsenic is detoxified via methylation is being questioned, as MMA(III) and DMA(III) may be activated intermediates that could be associated with the carcinogenicity of As during the methylation pathway in vivo [2]. Because of these recent findings, researchers have attempted to use analytical procedures to preserve the native oxidation state in both biological and dietary matrices.
In previous studies, some varieties of carrots were found to contain monomethylarsonate {MMA(V)} and a species that was tentatively identified as MMA(III), in addition to inorganic arsenic [3]. This presentation will provide arsenic speciation data in carrots using a mass balance approach. The emphasis of the presentation will be on the chromatographic data, which indicates that both MMA(III) and monomethylthioarsenic acid {MMTA} are present in low levels in some carrot extracts. Data for carrot extracts fortified with MMA(III) will be presented demonstrating co-elution via IC-ICP-MS. Co-elution on a secondary chromatographic column using IC-ICP-MS will be presented to further substantiate the presence of MMA(III) in the carrot extract. Similar data will be presented for the occurrence of MMTA in carrot extracts. To date, molecular confirmation via IC-ESI-MS/MS has been unsuccessful due to the low concentrations of MMA(III) and MMTA in carrots.

[1] K. Kuroda, G. Endo, et al., Toxicology and Applied Pharmacology, 2004, 198, 345.

[2] T.G. Rossman, A.N. Uddin, F.J. Burns, Toxicology and Applied Pharmacology, 2004, 198, 394.

[3] N.P. Vela, D.T. Heitkemper and K.R. Stewart, Analyst, 2001, 126, 1011.

PRESENTATION Extraction and Speciation of Arsenic Containing Drinking Water Treatment Solids By Ic-ICP-MS 01/08/2006
CREED, JOHN T., P. A. CREED, C. GALLAWA, AND C. A. SCHWEGEL. Extraction and Speciation of Arsenic Containing Drinking Water Treatment Solids By Ic-ICP-MS. Presented at 2006 Winter Conference on Plasma Spectrochemistry, Tucson, AZ, January 08 - 14, 2006.
Abstract: In 2001, the U.S. Environmental Protection Agency (EPA) passed the Arsenic Rule, which established a maximum contaminant level of 105g/L. Compliance with this regulation has caused a number of drinking water utilities to investigate potential treatment options. The adsorption of arsenic onto iron oxide-hydroxides via coagulation is one of the most common means of achieving arsenic removal. Some of the arsenic containing solids formed during coagulation (treatment related or natural) may enter the distribution system because of inadequate filtration. Compliance with the Arsenic Rule may cause some drinking water utilities to alter basic water quality parameters such as pH and phosphate. This may affect the mobility of the arsenic on the distribution system solids. One factor that could influence the mobility is the oxidation state of the arsenic attached to the solids. Therefore, an improved understanding of the oxidation state of the adsorbed arsenic is critical to assessing these solids as potential exposure sources. The oxidation state of the arsenic on these solids can be estimated by either X-ray Absorption Near Edge Structure (XANES) or on-line sequential extraction coupled with IC-ICP-MS. The latter is a cost effective means of evaluating the oxidation state of the arsenic associated with these solids. To date, the sequential extraction technique has been used to estimate the As(III)/As(V) on iron based treatment media used to enhance removal efficiencies within drinking water treatment plants. This presentation will extend this application to arsenic containing distribution system solids which have recently been shown to contain elevated levels of arsenic.[1]

PRESENTATION Detection and Quantification of a Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interaction of Arsenosugars With Sulfide 01/08/2006
CONKLIN, S., P. A. CREED, AND JOHN T. CREED. Detection and Quantification of a Thio-Arsenosugar in Marine Mollusks By Ic-ICP-MS With An Emphasis on the Interaction of Arsenosugars With Sulfide. Presented at 2006 Winter Conference on Plasma Spectrochemistry, Tuscan, AZ, January 08 - 14, 2006.
Abstract: Arsenosugars can make up a significant portion of the total arsenic in shellfish. These arsenosugars can be present in their oxide or sulfide form. IC-ICP-MS and IC-ESI-MS/MS data will be presented that indicates the presence of As(328-S) and As(328) in three species of marine mollusk. The sulfide form of the arsenosugar was found to be 12, 14 and 30% relative to the oxide in these samples. These findings initiated more fundamental studies surrounding the potential formation of arsenic sulfides during the extraction procedure. The extraction procedure of interest utilizes a tertramethylammonium hydroxide (TMAOH) solution (pH ~ 12.5) to quantitatively solubilize the arsenicals from the difficult to extract shellfish. At this point, the TMAOH extracts contain a mixture of arsenosugar oxides and sulfides. The second step utilizes acetic acid to precipitate the proteins (in order to minimize chromatographic column fouling) and produces an extract with a pH of 4. At this pH, the initial equilibrium between the oxide/sulfide favors the sulfide, but with time, the equilibrium shifts back to the oxide. This data clearly indicated that the native distribution of oxide to sulfide was influenced by the two step extraction procedure. Extractions utilizing a far less chemically aggressive 50/50 MeOH/H2O extraction fluid indicated an equilibrium that favored the oxide, but with this extraction fluid approximately 30% of the arsenic remained in the mollusk tissue. The fundamental questions raised by these results are: "What extraction parameters influence the distribution of oxide/sulfide and what co-extractant promotes an equilibrium shift towards the sulfide at low pH?".
Results will be presented that indicate that the TMAOH extraction liberates between 0.5-2 ppm sulfide. At a pH of 12, the sulfide is present as S2- and is unlikely to react with the arsenosugar oxide to produce the arsenosugar sulfide. However, the acidification of these extracts converts S2- to H2S, which reacts with the arsenosugars oxide and accounts for the conversion to the arsenosugar sulfide upon acidification. These results are significant in that extraction procedures which liberate both sulfide and arsenosugars from seafood samples are likely to produce enhanced arsenosugar sulfides if the pH is not adjusted basic to minimize the production of H2S. These findings may also extend to other arsenic oxides depending on the H2S concentrations.

 

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